Biden and the cost of war

I watched the vice presidential debate last night and thought both candidates came across well. One thing that caught my interest was a statement by Joe Biden that the cost of three weeks of war in Iraq was the same as the total cost in Afghanistan. That just did not seem right. Googling, I found a site that gave the budgeted cost of the Iraq war through 2007 as $448.6 billion, and the budgeted cost of the Afghanistan war through 2007 as $126.8. That is not at all consistent with what Biden said. However, looking further, I found an explanation at PBS:

Senator Biden appears to be contrasting the spending on combat operations in Iraq with the spending on reconstruction and other diplomatic activities ("building that country"). Over seven years (not including FY 09), according to the Congressional Research Service, the United States has spent $11.8 billion on foreign aid and diplomatic operations in Afghanistan. The Pentagon in FY 08 has spent $145 billion in Iraq. This works out to about $8.4 billion per three week period.

So Biden can justify his numbers, and the first time he uses those numbers it makes sense because his point seems to be that we have not spent enough on infrastructure:

He said we need more troops. We need government-building. We need to spend more money on the infrastructure in Afghanistan.

Look, we have spent more money -- we spend more money in three weeks on combat in Iraq than we spent on the entirety of the last seven years that we have been in Afghanistan building that country.

Let me say that again. Three weeks in Iraq; seven years, seven years or six-and-a-half years in Afghanistan. Now, that's number one.

But then he repeats the numbers in the context of needing more troops, and here this comparison of numbers makes no sense at all and is misleading:

Barack Obama was saying we need more troops there. Again, we spend in three weeks on combat missions in Iraq, more than we spent in the entire time we have been in Afghanistan. That will change in a Barack Obama administration.