Every civilian's death diminishes us, collectively.

In Afghanistan you are not rebuilding, you are building. There is very limited infrastructure and extreme terrain, with deserts in the south and mountains so high in some areas that helicopters don't even fly well at a certain altitude because the air becomes so thin. The country has a serious problem of illiteracy, especially after so many years of war and Taliban rule.

Let's remember that the reason we are there is that we have vital interests in Afghanistan, hugely important national interests, as do the other countries involved.

The Sunni Arabs began to realize that they had made a huge mistake by not voting in the election of 2005 and by not being part of the new Iraq. They had reasons for this: They were effected by the disestablishment of the military and by de-Baathification (the dismantling of Saddam Hussein's party) in winter 2007-2007. They increasingly recognized that their future lay in being part of the solution rather than a continuing part of the problem.

I just don't know whether it was all destroyed years ago - I mean, there's no question that there were chemical weapons years ago - whether they were destroyed right before the war, (or) whether they're still hidden.

I think Putin wants to recreate as much of the Soviet Union as he can through a variety of different means. He's invaded parts of Georgia, took Crimea, southeastern Ukraine, bases in other countries.

There are some ideas that will translate from Iraq to Afghanistan and there are many that will not. The first lesson of counterinsurgency, in fact, is that every situation is truly unique, has its own context, its own specific set of factors - and you have to understand that context in enormous detail to be able to craft a sound and comprehensive approach.