The lesson of Iraq:
McCain: You can't have a failed strategy. We will come home in victory and with honor.
Obama: We have a fundamental difference. I opposed this war six years ago. Don't know cost, exit strategy, impact on relations around the world, hadn't finished the job in Afghanistan- with Bin Laden / Al Queda. Soon to have spent over 1 trillion dollars; lost many lives; Al Queda is stronger than any time since 2001.
The lesson of Iraq: Never hesitate to use military force to keep our people safe, but must use our military wisely, and we did not use our forces wisely by going into Iraq.
On going into Pakistan, Obama seems to box McCain in after McCain tries to set Obama up as dangerously wanting to go into Pakistan. He wants to suggest that Obama "doesn't understand" Pakistan was a failed state, and other issues. We'll hear the "doesn't understand" again, I imagine. But Obama said he'd go into Pakistan to get Bin Laden, if Pakistan refused to do so. How does McCain attack that, consistent with his true beliefs?
As McCain is focused on showing that Obama "doesn't understand", Obama is, sometimes subtly, focusing on the need for "good judgment."
(I note that Obama is wearing an American flag lapel pin; McCain is not.)
Both candidates are "holding their own" thus far; I'd suggest Obama is making the better impression thus far -- he's being direct, not overly intellectual, not pausing unnecessarily -- and he's replaced his "um's" from the primary debates with "and" -- which is far less irritating. Obama is certainly showing that he can stand toe-to-toe with John McCain on economic and foreign policy issues thus far.