何亮亮(凤凰卫视评论员)
2009年4月30日

中国当前的读书风气以实用、消遣为主流,无论是成年人还是孩子,都是如此。蔡伟的事迹令人耳目一新,如果中国每年能够出现和培养一百个蔡伟这样的学子,如果有关蔡伟的报道能够带动更多的年轻人按自己的兴趣读书而学校也能够为他们创造条件,如果中国的社会能够真正地不拘一格降人才,中华民族就大有希望。

前些时候,内地一个只有高中毕业的古文字研究爱好者被批准破格参加博士生考试,当时这则消息就引起我的关注。

辽宁锦州一个38岁的下岗工人,从小喜欢研究中国的古文字,20年前高考没有考上大学,此后一直打杂工包括蹬三轮车维生,但始终没有放弃古文字领域的研究。蔡伟曾经多次和著名古文字学者、上海复旦大学的裘锡圭教授商讨古文字方面的问题,深得裘教授的欣赏,裘还为他创造条件在复旦大学的出土文献与古文字研究中心参与《长沙马王堆汉墓简帛集成》专案的研究工作。裘锡圭一方面鼓励蔡伟报名参加博士生考试,同时邀得另外两名专家的连署,要求教育部特批只有高中学历的蔡伟参加考试并且获得教育部的同意。最新的消息是:4月23日,复旦大学经过专家考试与招生领导小组的讨论,将蔡伟列入今年博士生拟录取名单。这个消息使我非常兴奋,从蔡伟身上看到了真正热心读书的中国青年一代,从裘锡圭教授身上看到了中国学术界的希望。

学校官场化 一切为升学率

近十几年来,中国的高等教育大发展,官场化和学店化的趋势越来越严重,中国的学术界对学者的要求以论文的数量作为标准;教授不教书,学生不好好读书,一切向钱看,使得中国在国际学术界地位不高,中国至今无法出现诺贝尔科技奖的学者。

另一方面,整个社会弥漫着浮躁的习气,读书只是为了考上名校,读书只是为了以后当官或谋取一份好的工作,孩子们无法按照自己的兴趣读书,家长和学校也不鼓励学生按兴趣读书,一切都是为了升学率。结果尽管中国每年培养的工程师和教师人数在世界上名列前茅,中国的自主创新科技却仍然远远落后于先进国家,中国的学生仍然以死读书、会考试而不是富于创新精神而出名。

真正做学问的精神

蔡伟身上体现了真正做学问的精神。裘锡圭教授这样评价蔡伟:「现在搞古文字学的,许多人名义上是教授了,实际上没有他这个水平。有些地方,我也没有他这个水平。」复旦大学出土文献与古文字研究中心主任刘钊说,蔡伟没有受过专业的学术训练,很多最新出土的文献也没机会读到,但自学了大量传世典籍,许多到了倒背如流的程度。「蔡伟心无旁骛,对古书的文字、句法及古人用语习惯都烂熟于心,甚至比许多专业研究者更熟悉,他较常人更容易融入到古代的语言环境中,对于古人的行为和想法更能够感同身受,时间久了,对古书有了触类旁通的能力。」当然蔡伟还需要专业的训练,包括补上语言学、历史学和考古学的课程,外语学习也是不可或缺的,学校让他攻读日语,因为日本在中国的古文字研究方面成绩突出,今后的交流需要外语。

蔡伟体现了失传的读书人精神

蔡伟并非出身书香门第,父母都是普通市民,但他从小就对古文字有兴趣,从不感到研究古文字枯燥。高中毕业后近20年的时间里,他对古文字的钻研从没有间断过。他的学习条件不好,图书馆里有很多古籍找不到,有些书又不能外借,就只好坐在图书馆里,把整本整本的书抄下来。他的妻子张悦找到了蔡伟的一本读书笔记,里面抄录了很多「甲骨文」。他的儿子说:我爸一看书就看一大天。

有了这种精神才能真正读书做学问,才能成为学者,才能让中国的传统文化继承和发扬,才能把外来的优秀文化介绍到中国。蔡伟体现了一种几乎失传的中国读书人的精神,而裘锡圭和复旦大学能够慧眼识人,教育部能够批准蔡伟破格参加考试,都令人激赏。

nucifera: 这无疑是很重要的报导,但毕竟这份报导挺久的了。去年的时候The economist也有做过类似的报导,那时这个概念比起先前获得了更多的证实和肯定。

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By GINA KOLATA
Published: December 21, 2007

Within the next few months, researchers at three medical centers expect to start the first test in patients of one of the most promising — and contentious — ideas about the cause and treatment of cancer.

The idea is to take aim at what some scientists say are cancerous stem cells — aberrant cells that maintain and propagate malignant tumors.

Although many scientists have assumed that cancer cells are immortal — that they divide and grow indefinitely — most can only divide a certain number of times before dying. The stem-cell hypothesis says that cancers themselves may not die because they are fed by cancerous stem cells, a small and particularly dangerous kind of cell that can renew by dividing even as it spews out more cells that form the bulk of a tumor. Worse, stem cells may be impervious to most standard cancer therapies.

Not everyone accepts the hypothesis of cancerous stem cells. Skeptics say proponents are so in love with the idea that they dismiss or ignore evidence against it. Dr. Scott E. Kern, for instance, a leading pancreatic cancer researcher at Johns Hopkins University, said the hypothesis was more akin to religion than to science.

At stake in the debate is the direction of cancer research. If proponents of the stem-cell hypothesis are correct, it will usher in an era of hope for curing once-incurable cancers.

If the critics are right, the stem-cell enthusiasts are heading down a blind alley that will serve as just another cautionary tale in the history of medical research.

In the meantime, though, proponents are looking for ways to kill the stem cells, and say that certain new drugs may be the solution.

“Within the next year, we will see medical centers targeting stem cells in almost every cancer,” said Dr. Max S. Wicha, director of the University of Michigan Comprehensive Cancer Center, one of the sites for the preliminary study that begins in the next few months (the other participating institutions are Baylor College of Medicine in Houston and the Dana-Farber Cancer Institute in Boston).

“We are so excited about this,” Dr. Wicha said. “It has become a major thrust of our cancer center.”

At the National Cancer Institute, administrators seem excited, too.

“If this is real, it could have almost immediate impact,” said Dr. R. Allan Mufson, chief of the institute’s Cancer Immunology and Hematology Branch.

The cancer institute is financing the research, he said, and has authorized Dr. Mufson to put out a request for proposals, soliciting investigators to apply for cancer institute money to study cancer stem cells and ways to bring the research to cancer patients. The institute has agreed to contribute $5.4 million.

“Given the current fiscal situation, which is terrible, it’s a surprising amount,” Dr. Mufson said. “We actually asked for less,” he added, but the cancer institute’s executive committee asked that the amount be increased.

Proponents of the hypothesis like to use the analogy of a lawn dotted with dandelions: Mowing the lawn makes it look like the weeds are gone, but the roots are intact and the dandelions come back.

So it is with cancer, they say. Chemotherapy and radiation often destroy most of a tumor, but if they do not kill the stem cells, which are the cancer’s roots, it can grow back.

Cancerous stem cells are not the same as embryonic stem cells, the cells present early in development that can turn into any cell of the body. Cancerous stem cells are different. They can turn into tumor cells, and they are characterized by distinctive molecular markers.

The stem-cell hypothesis answered a longstanding question: does each cell in a tumor have the same ability to keep a cancer going? By one test the answer was no. When researchers transplanted tumor cells into a mouse that had no immune system, they found that not all of the cells could form tumors.

To take the work to the next step, researchers needed a good way to isolate the cancer-forming cells. Until recently, “the whole thing languished,” said Dr. John E. Dick, director of the stem cell biology program at the University of Toronto, because scientists did not have the molecular tools to investigate.

But when those tools emerged in the early 1990s, Dr. Dick found stem cells in acute myelogenous leukemia, a blood cancer. He reported that such cells made up just 1 percent of the leukemia cells and that those were the only ones that could form tumors in mice.

Yet Dr. Dick’s research, Dr. Wicha said, “was pretty much ignored.” Cancer researchers, he said, were not persuaded — and even if they had accepted the research — doubted that the results would hold for solid tumors, like those of the breast, colon, prostate or brain.

That changed in 1994, when Dr. Wicha and a colleague, Dr. Michael Clarke, who is now at Stanford, reported finding cancerous stem cells in breast cancer patients.

“The paper hit me like a bombshell,” said Robert Weinberg, a professor of biology at M.I.T. and a leader in cancer research. “To my mind, that is conceptually the most important paper in cancer over the past decade.”

Dr. Weinberg and others began pursuing the stem-cell hypothesis, and researchers now say they have found cancerous stem cells in cancers of the colon, head and neck, lung, prostate, brain, and pancreas.

Symposiums were held. Leading journals published paper after paper.

But difficult questions persisted. One problem, critics say, is that the math does not add up. The hypothesis only makes sense if a tiny fraction of cells in a tumor are stem cells, said Dr. Bert Vogelstein, a colon cancer researcher at Johns Hopkins who said he had not made up his mind on the validity of the hypothesis.

But some studies suggest that stem cells make up 10 percent or even 40 percent or 50 percent of tumor cells, at least by the molecular-marker criterion. If a treatment shrinks a tumor by 99 percent, as is often the case, and 10 percent of the tumor was stem cells, then the stem cells too must have been susceptible, Dr. Vogelstein says.

Critics also question the research on mice. The same cells that can give rise to a tumor if transplanted into one part of a mouse may not form a tumor elsewhere.

“A lot of things affect transplants,” Dr. Kern, the Johns Hopkins researcher, said, explaining that transplanting tumors into mice did not necessarily reveal whether there were stem cells.

Other doubts have been raised by Dr. Kornelia Polyak, a researcher at the Dana-Farber Cancer Institute. Dr. Polyak asked whether breast cancer cells remain true to type, that is, whether stem cells remain stem cells and whether others remain non-stem cells? The answer, she has found, is “not necessarily.”

Cancer cells instead appear to be moving targets, changing from stem cells to non-stem cells and back again. The discovery was unexpected because it had been thought that cell development went one way — from stem cell to tumor cell — and there was no going back.

“You want to kill all the cells in a tumor,” Dr. Polyak said. “Everyone assumes that currently-used drugs are not targeting stem cell populations, but that has not been proven.”

“To say you just have to kill the cancer stem cell is oversimplified,” she added. “It’s giving false hope.”

The criticisms make sense, Dr. Weinberg said. But he said he remained swayed by the stem cell hypothesis.

“There are a lot of unanswered questions, mind you,” he said. “Most believe cancer stem cells exist, but that doesn’t mean they exist. We believe it on the basis of rather fragmentary evidence, which I happen to believe in the aggregate is rather convincing.”

Dr. Wicha said he was convinced that the hypothesis was correct, and said it explained better than any other hypothesis what doctors and patients already know.

“Not only are some of the approaches we are using not getting us anywhere, but even the way we approve drugs is a bad model,” he said. Anti-cancer drugs, he noted, are approved if they shrink tumors even if they do not prolong life. It is the medical equivalent, he said, of mowing a dandelion field.

He said the moment of truth would come soon, with studies like the one planned for women with breast cancer.

The drug to be tested was developed by Merck to treat Alzheimer’s disease. It did not work on Alzheimer’s but it kills breast cancer stem cells in laboratory studies, Dr. Wicha says.

The study will start with a safety test on 30 women who have advanced breast cancer. Hopes are that it will be expanded to find out if the drug can prolong lives.

“Patient survival,” Dr. Wicha said, “is the ultimate endpoint.”

Smaointe…

四月 25, 2009

多年前在钢琴老师家听了Enya的《Shepherd Moons》,当时就特别喜欢“Smaointe…”这首曲。在后来的日子里,我翻找了好多Enya的精选集,都不见这曲的踪影。这可是Enya最好的作品啊,至少我是这么觉得。当Uillean pipes的声音响起时,思念和悲伤随晚风飘散,不知是否能抵达它们想去的地方。

我听歌不爱听歌词。也因为这独特的pattern,我也偏好听一些我听不懂的语言,就像这一首。但是我还是找来了这歌词的英译。不过,要完整不受干扰(不必要的联想作用)地聆听此曲,不看歌词会更好。

Irish Gaelic

Smaointe…
(D’Aodh Agus Do Mháire Uí Dhúgain)

Éist le mo chroí,
Go brónach a choích’
Tá mé caillte gan tú
‘s do bhean chéile.
An grá mór i do shaoil
Treoraí sé mé.
Bígí liomsa i gcónaí
Lá ‘s oích’.

Curfá:

Ag caoineadh ar an uaigneas mór
Na deora, go brónach
‘Na gcodladh ins an uaigh ghlas chiúin
Faoi shuaimhneas, go domhain.
Aoibhneas a bhí
Ach d’imigh sin
Sé lean tú
Do fhear chéile.
An grá mór i do shaoil
Treoraí sé mé.
Bígí liomsa i gcónaí
Lá ‘s oích’.

Curfá

Smaointe, ar an lá
‘Raibh sibh ar mo thaobh
Ag inse scéil
Ar an dóigh a bhí
Is cuimhin liom an lá
Gan ghá ‘s gan ghruaim
Bígí liomsa i gcónaí
Lá ‘s oích’.

Translation:

A thought

(To my maternal grandparents,
literally: “For Hugh and Mary Duggan”)

Listen to my heart,
Forever sad
I’m lost without you
and your wife.
The great love in your lives [1]
Will guide me.
Be (plural) with me always
Day and night.

Chorus:

Weeping due to the great loneliness
The tears, sorrowfully
Asleep in the quiet green grave
In a deep peace.
There was blissfulness
But that is gone
You followed
Your husband.
The great love in your lives
Will guide me.
Be (plural) with me always
Day and night.

Chorus

A thought, on the day
You were (both) at my side
Telling tales
Of how things were.
I remember the day
Carefree and happy [2]
Be (plural) with me always
Day and night.

[1] The meaning of this phrase in this context is “the love that was shown by the two of you”.
[2] Literally “without need and without gloom”.

April 22, 2009
From The New York Times

Speaking of financial crises and how they can expose weak companies and weak countries, Warren Buffett once famously quipped that “only when the tide goes out do you find out who is not wearing a bathing suit.” So true. But what’s really unnerving is that America appears to be one of those countries that has been swimming buck naked — in more ways than one.

Credit bubbles are like the tide. They can cover up a lot of rot. In our case, the excess consumer demand and jobs created by our credit and housing bubbles have masked not only our weaknesses in manufacturing and other economic fundamentals, but something worse: how far we have fallen behind in K-12 education and how much it is now costing us. That is the conclusion I drew from a new study by the consulting firm McKinsey, entitled “The Economic Impact of the Achievement Gap in America’s Schools.”

Just a quick review: In the 1950s and 1960s, the U.S. dominated the world in K-12 education. We also dominated economically. In the 1970s and 1980s, we still had a lead, albeit smaller, in educating our population through secondary school, and America continued to lead the world economically, albeit with other big economies, like China, closing in. Today, we have fallen behind in both per capita high school graduates and their quality. Consequences to follow.

For instance, in the 2006 Program for International Student Assessment that measured the applied learning and problem-solving skills of 15-year-olds in 30 industrialized countries, the U.S. ranked 25th out of the 30 in math and 24th in science. That put our average youth on par with those from Portugal and the Slovak Republic, “rather than with students in countries that are more relevant competitors for service-sector and high-value jobs, like Canada, the Netherlands, Korea, and Australia,” McKinsey noted.

Actually, our fourth-graders compare well on such global tests with, say, Singapore. But our high school kids really lag, which means that “the longer American children are in school, the worse they perform compared to their international peers,” said McKinsey.

There are millions of kids who are in modern suburban schools “who don’t realize how far behind they are,” said Matt Miller, one of the authors. “They are being prepared for $12-an-hour jobs — not $40 to $50 an hour.”

It is not that we are failing across the board. There are huge numbers of exciting education innovations in America today — from new modes of teacher compensation to charter schools to school districts scattered around the country that are showing real improvements based on better methods, better principals and higher standards. The problem is that they are too scattered — leaving all kinds of achievement gaps between whites, African-Americans, Latinos and different income levels.

Using an economic model created for this study, McKinsey showed how much those gaps are costing us. Suppose, it noted, “that in the 15 years after the 1983 report ‘A Nation at Risk’ sounded the alarm about the ‘rising tide of mediocrity’ in American education,” the U.S. had lifted lagging student achievement to higher benchmarks of performance? What would have happened?

The answer, says McKinsey: If America had closed the international achievement gap between 1983 and 1998 and had raised its performance to the level of such nations as Finland and South Korea, United States G.D.P. in 2008 would have been between $1.3 trillion and $2.3 trillion higher. If we had closed the racial achievement gap and black and Latino student performance had caught up with that of white students by 1998, G.D.P. in 2008 would have been between $310 billion and $525 billion higher. If the gap between low-income students and the rest had been narrowed, G.D.P. in 2008 would have been $400 billion to $670 billion higher.

There are some hopeful signs. President Obama recognizes that we urgently need to invest the money and energy to take those schools and best practices that are working from islands of excellence to a new national norm. But we need to do it with the sense of urgency and follow-through that the economic and moral stakes demand.

With Wall Street’s decline, though, many more educated and idealistic youth want to try teaching. Wendy Kopp, the founder of Teach for America, called the other day with these statistics about college graduates signing up to join her organization to teach in some of our neediest schools next year: “Our total applications are up 40 percent. Eleven percent of all Ivy League seniors applied, 16 percent of Yale’s senior class, 15 percent of Princeton’s, 25 percent of Spellman’s and 35 percent of the African-American seniors at Harvard. In 130 colleges, between 5 and 15 percent of the senior class applied.”

Part of it, said Kopp, is a lack of jobs elsewhere. But part of it is “students responding to the call that this is a problem our generation can solve.” May it be so, because today, educationally, we are not a nation at risk. We are a nation in decline, and our nakedness is really showing.

nucifera: 放出这篇报导的目的无他,只想借此说明一件事:我们人类对于地震的预测,还是很无能为力,更别提能准确预测7月22日的那一场地震。

当然,这篇报导还有另一个重点:水坝的存在能引发地震,或者说,促使地震提前发生。先前已经有研究初步显示,去年四川大地震的爆发,或许和附近的一个水坝有关。

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April 14, 2009
By KENNETH CHANG

Almost all earthquakes are small. A small segment of a fault, miles underground, jerks a little, the rumble imperceptible at the surface. But with a few quakes, the fault continues breaking, the ground jumps several feet and the world shakes in cataclysm.

“How does a rupture go from an inch a year to 3,000 miles per hour in a few seconds?” asked Ross S. Stein, a geophysicist at the United States Geological Survey.

No one knows.

This gap in knowledge makes earthquake prediction a frustrating and chancy exercise, and complicates the effort to calculate the risk that a human construction like a water reservoir or a geothermal power plant could inadvertently set off a deadly quake.

Last month, Giampaolo Giuliani, a technician who works on a neutrino experiment at the Gran Sasso National Laboratory in Italy, issued an urgent warning that a large earthquake was about to strike the Abruzzo region. The prediction was based on measurements he had made of high levels of radon gas, presumably released from rocks that were being ground up by the stresses of an incipient quake.

On April 6, a magnitude 6.3 earthquake hit L’Aquila in central Italy, killing almost 300 people. Mr. Giuliani claimed vindication for his prediction, which had been discounted by officials.

But earthquake experts like Dr. Stein are skeptical. Scientists studied radon as a possible earthquake warning signal as far back as the 1970s, and while they found convincing cases of radon releases before some earthquakes — for example, levels of radon in groundwater were 10 times normal before the earthquake that hit Kobe, Japan, in 1995 — the correlations were not strong enough or clear enough for useful predictions.

One instance of confusing radon signals occurred in 1979. Two detectors in Southern California, 20 miles apart, measured unusually high levels of radon beginning in the summer. The radon levels then decreased in October, shortly before three earthquakes struck.

One earthquake, of magnitude 6.6, occurred 180 miles to the southeast, and the two smaller ones, of magnitudes 4.1 and 4.2, were 40 miles away. In addition, a radon detector close to one of the smaller quakes did not observe high radon levels, although it did observe a radon drop a few days earlier.

That left scientists puzzled about how they could construct a prediction out of the rising and falling radon levels. Data on other gases like carbon dioxide and on electromagnetic emissions that have sometimes been detected before earthquakes are also confusing.

“You can’t hang your hat on it unless it’s a reliable precursor and it happens before most earthquakes and it doesn’t happen at other times,” said Susan Hough, a seismologist at the geological survey.

To complicate matters, Mr. Giuliani’s prediction was off in time and place. He had predicted that the quake would hit a week earlier in a town 30 miles away. Had officials acted on his prediction, said Richard M. Allen, a professor of geophysics at the University of California, Berkeley, “you would have evacuated the wrong town and you would have evacuated the wrong town at the wrong time.”

While prediction remains elusive, scientists have learned that human activity can set off an earthquake. In December 2006, a geothermal energy project in Basel, Switzerland, started injecting water three miles into the ground. Some tiny tremors were expected, but the water was shut off when one of the quakes reached a still minor magnitude of 2.7. A few hours later, a larger quake, at magnitude 3.4, shook Basel, causing minor damage to buildings.

A couple of months later, there were two more magnitude 3 earthquakes. Researchers at the Swiss Federal Institute of Technology in Zurich calculate that the area will experience a slightly greater number of small earthquakes over the next 20 to 40 years as a result of the brief geothermal project, which remains halted.

The worry is that one of these small earthquakes could cascade into a big earthquake like the one that badly damaged Basel in 1356. Conversely, the small earthquakes could instead be relieving stress along a fault, reducing the likelihood of a larger quake.

“With the current knowledge, I can’t really tell you,” said Jochen Woessner, one of the Swiss scientists.

Geologists do not know how the pieces of the Earth’s crust that usually squeeze together tightly with high friction slip past each other smoothly during a large earthquake, as if sandpaper suddenly changed to Teflon. “It looks like friction is more a complicated beast than anyone would have imagined,” Dr. Stein said.

A core dug up from the San Andreas fault in California revealed the presence of talc, which could be acting as a lubricant during an earthquake. But from one core, scientists cannot tell whether this is typical of rocks around earthquake faults.

At a meeting of the Seismological Society of America last week in Monterey, Calif., a lively debate continued about whether big earthquakes are fundamentally different from small earthquakes or whether a big earthquake is just a small earthquake that did not stop. If big earthquakes are different, then it might be possible to detect them in the first few seconds of seismic waves and send out a warning. People would not have time to evacuate, but they might have enough time before the heaviest shaking to move to a safer location in a doorway or under a desk.

Reservoirs are also believed to induce some earthquakes. Most seismologists believe that a magnitude 6.5 earthquake in India in 1967 that killed about 200 people was set off by the weight of water in a reservoir that had been filled a few years earlier. A reservoir cannot generate an earthquake by itself, but it can act as a trigger to release accumulated tectonic stresses and hasten an earthquake by years or centuries.

More controversial is the assertion by some scientists that a magnitude 7.9 earthquake in Sichuan province in China last year that killed about 80,000 people was set off by the 320 million tons of water in a nearby reservoir.

Leonardo Seeber, a research scientist at the Lamont-Doherty Earth Observatory at Columbia University, is not sure about the Sichuan earthquake, but he believes that scientists and officials need to take more account of the risk of induced earthquakes.

For example, Dr. Seeber wonders whether a swarm of magnitude 4 earthquakes a couple of weeks ago around the Salton Sea in Southern California, close to one end of the San Andreas, might have been caused in part by a nearby geothermal power plant.

Extraction of oil from the ground may have set off other earthquakes, Dr. Seeber said. In the coming years, the proposed strategy to reduce global warming by capturing carbon dioxide from power plants and pumping it into the ground could create new earthquake risks.

So far, experiments in this kind of carbon sequestration have focused on whether it will work to keep carbon dioxide out of the air for centuries. But Dr. Seeber said this technology “has huge implications for triggering earthquakes.”

April 19, 2009
From The New York Times

I’ve been thinking lately of starting a new school of foreign service to train U.S. diplomats. My school, though, would be very simple. It would consist of a single classroom with a desk and a chair. At the desk would be a teacher, pretending to be a foreign leader. The student would come in and have to persuade the foreign leader to do something — to pull this or that lever. At one point, the foreign leader would nod vigorously in agreement and then reach behind him and pull the lever — and it would come off the wall in his hands. Or, he would nod vigorously and say, “Yes, yes, of course, I will pull that lever,” but then would only pretend to do so.

The student would then have to figure out what to do next. …

I’m wondering if President Obama and Secretary of State Hillary Clinton aren’t those students, trying to deal with the leaders of Pakistan, Afghanistan, Iran and North Korea. I say that not to criticize but to sympathize. “Mama, don’t let your children grow up to be diplomats.”

This is not the great age of diplomacy.

A secretary of state can broker deals only when other states or parties are ready or able to make them. In the cold war, an age of great powers, grand bargains and reasonably solid client states, there were ample opportunities for that — whether in arms control with the Soviet Union or peacemaking between our respective client states around the globe. But this is increasingly an age of pirates, failed states, nonstate actors and nation-building — the stuff of snipers, drones and generals, not diplomats.

Hence the déjà vu all over again quality of U.S. foreign policy right now — the sense that when it comes to our major problems (Afghanistan and Pakistan and North Korea and Iran), we just go around and around, buying the same carpets from the same people, over and over, but nothing changes.

“We are dealing with states and leaders who either cannot deliver or will not deliver,” notes the Johns Hopkins University foreign policy professor Michael Mandelbaum. “The issues we have with them look less like problems that can be solved and more like conditions that we have to manage.”

The ones who can’t deliver — the leaders of Afghanistan and Pakistan — are the ones who promise to do all sorts of good things, and pull all sorts of levers, but at the end of the day the levers come off the wall because the governments in these countries have only limited powers. The ones who won’t deliver — Iran and North Korea — time and again tell us: “Yes, we need to talk.” But at the end of the day, their hostile relationships with America or the West are so central to the survival strategy of their regimes, so much at the core of their justifications for remaining in power, that it is not in their interest to deliver real reconciliation, but just to pretend to deliver it.

The only thing that could change this is a greater exercise of U.S. and allied power. In the case of Afghanistan and Pakistan, that power would have to be used to actually rebuild these states from the inside into modern nations. We would literally have to build the institutions — the pulleys and wheels — so that when the leaders of these states pulled a lever something actually happened, and the lever wouldn’t just break off in their hands.

And in the case of the strong states — Iran and North Korea — we would have to generate much more effective leverage from the outside to get them to change their behavior along the lines we seek. In both cases, though, success surely would require a bigger and longer U.S. investment of money and power, not to mention allies.

Instead, I fear that we are adopting a middle-ground strategy — doing just enough to avoid collapse but not enough to solve the problems. If our goal in Afghanistan and Pakistan is nation-building, so they will have self-sustaining moderate governments, we surely don’t have enough troops or resources inside devoted to either. If our goal is changing regime behavior in Iran and North Korea, we surely have not generated enough leverage from outside. North Korea’s defiant missile launch and Iran’s continued development of its nuclear capability testify to that.

So, in sum, we have four problem countries at the heart of U.S. foreign policy today that we don’t have the will or ability to ignore but seem to lack the leverage or the allies to decisively change. The big wild card — a critical mass of people who share our aspirations inside these countries, rising up and leading the fight, which is ultimately what tipped Iraq for the better — I don’t see. As such, I fear we are sliding into commitments in Afghanistan and Pakistan without a real national debate about the ends or the means or the exits. That is a recipe for trouble.

Given all that is on his plate, you cannot blame President Obama for looking for a middle ground — not wanting to abandon progressives and women in Afghanistan and Pakistan, but not wanting to get in too deeply. But history teaches that the middle ground can be a perilous place. Think of Iraq before the surge — not enough to win or lose, but just enough to be stuck.