On Tuesday of last week, Talib Hussein, a trusted Afghan soldier, launched a well-planned attack on his British soldier comrades, killing 3, and fled the camp.

A spokesman for the Taliban claimed that he was a “sleeper,” planted in the British ranks to carry out the killings.

This statement was evidently a little joke for credulous Western newsmen and politicians. Hussein is from the ethnic Hazaris, who are Shia Muslims. The Taliban are ethnic Pashtuns, who are Sunni Muslims. The Islamist militant Taliban consider Shiism to be an apostasy.

Furthermore, Afghanistan fought an extremely bloody ethnic civil war in the 1990s, and the Hazaris and Pashtuns were on opposite sides. Hussein is 23 years old, meaning that he was 9 years old in 1996 when the civil war ended. Hussein almost certainly had friends or family members who were tortured or killed by the Pashtuns they were fighting, or who tortured or killed Pashtuns.

So there’s no way that Hussein was part of the Taliban, unless he’s had a lobotomy, and there’s no way that the Taliban want him. The most likely reason for his attack on British forces is that they support President Hamid Karzai, who is Pashtun.

The fact that Afghanistan fought a recent ethnic civil war, while Iraq’s most recent generational crisis war was NOT a civil war, is one of the major differences between the two countries that explain why the “surge” strategy that worked in Iraq can’t work in Afghanistan.

In 2003, I wrote that a civil war was impossible in Iraq, and I repeated this many times. This was not a guess. No civil war has ever occurred throughout history, so far as is known, in less than 50 years after after a generational crisis war; or if a civil war begins, it fizzles quickly. Iraq’s last crisis war was the bloody Iran/Iraq war that ended in 1988, with 1.5 million deaths. A low-level civil war did begin in Iraq in 2007, but it fizzled quickly, as expected.

The same is true in Afghanistan — there’s no chance of a civil war today, less than 20 years after the bloody 1990s crisis civil war. The survivors of that war are extremely risk averse, just like the survivors of the 1980s Iran/Iraq war. In both cases, the survivors will spend their lives doing everything possible to make sure that no similar war ever occurs again. That’s the public mood in both countries.

It’s undoubtedly this similarity in public mood in Iraq and Afghanistan that leads many analysts to conclude that the same counter-insurgency strategy that worked in Iraq should also work in Afghanistan. But beneath the surface, there are dramatic differences.

As I wrote in my April, 2007, analysis of the Iraq war, “Iraqi Sunnis are turning against al-Qaeda in Iraq,” Iraq’s last two generational crisis wars were the Iran/Iraq war of the 1980s and the Great Iraqi Revolution of 1920. In both of those wars, the Iraqi Sunnis and Shias put aside their religious and ethnic differences and fought alongside one another against external enemies. Iraqis put Iraqi nationalism ahead of their religion both times.

Thus, when Abu Musab al-Zarqawi and al-Qaeda in Iraq triggered sectarian violence by bombing the Shiite al-Askariya shrine in Samarra in February, 2006, the violence never spiraled into a full-fledged civil war. But more important, it only took a few months for both Sunnis and Shias to realize that they were Iraqis together, and that their REAL enemy was their EXTERNAL enemy, al-Qaeda in Iraq. That’s how a post-crisis-war public mood works. America’s “surge” and counter-insurgency strategy gave the Iraqis an opportunity to do something that was going to happen sooner or later anyway — expel the external enemy through the “Anbar awakening.”

But none of that is possible in Afghanistan. Afghanistan’s last crisis war pitted Afghan against Afghan. The Taliban are not external enemies; they’re Pashtuns, the largest ethnic group in Afghanistan. And the thought that Pashtuns and Hazaris will unite and fight alongside each other to expel the Taliban is laughable. The same is true of other Persian ethnic groups, such as the Tajiks. They may force themselves to get along with one another rather than risk another civil war, but they will always be bitter enemies.

Even worse, Pakistan is right next door, and the Pakistani Taliban/Pashtuns are in a generational Crisis era. Pakistan’s last generational crisis war was the war between Muslims and Hindus that followed Partition, the 1947 partitioning of the Indian subcontinent into Pakistan and India. This was quite possibly the bloodiest war of the 20th century, and generational theory predicts that this war will be re-fought in the not too distant future. The Taliban from Pakistan are thus even less willing than the Afghan Taliban to tolerate the Hazaris or the Tajiks.

None of this can be either caused or prevented by American politicians. This dynamic is the same under President Bush, President McCain, or President Obama.

This dynamic also explains why it could be disastrous to withdraw from Afghanistan. If Afghanistan were isolated, it wouldn’t matter much. But a Nato withdrawal would hand the Taliban an enormous victory that would reverberate from central Asia’s volatile Fergana Valley, into Pakistan, through the disputed Kashmir region, and across India.

Hindus have historically been allied with Shia Muslims against Sunni Muslims, and India would be forced to protect the Hazari and Tajiks in Afghanistan, and that would infuriate the Pakistanis, who are already on the edge of war with India.

Like it or not, Nato and the west are trapped in a losing situation in Afghanistan that really has little in common with Iraq. To paraphrase an old song, you can check in to Hotel Afghanistan, but you can’t check out.