I think it's true, we did kill or capture a lot of them over the past few years. Some called Iraq "flypaper" and it sure worked that way, drew Al Qaeda there, and we could kill them more easily when they are all in one place.
They thought they can make us leave by their suicide attack tactics, which would have worked under a Dem administration, but they miscalculated, they didn't count on President Bush's determination.
"Flypaper" is a pretty close description of our strategery. The Afganistan raid and liberation left a lot of terrorists loose--scattered in fact. It was necessary to clean that up as well as to attract terrorists to Iraq to die from Saudi, Sudan, Iran, Syria, etc etc.
In order for the strategery to work well the US had to appear weak and vulnerable in Iraq. The unwitting Dims and MSM helped us out there. People wonder why Bush had not defended himself in the first years of the Iraq war--it was so he could get the other side(s) to keep investing in a losing hand. This works much better than if the Islamists had retreated, bided their time, and regrouped for a bigger 911.
As explain the war to some of my propaganda influenced friends, your neighbors house is full of rats and they are powerless to help themselves. Now the rats are starting to get into your house. Where do you put the cheese and traps, your house or theirs?
Well at least most of them get it.