Constitutional Violation???

At first I thought this was a joke, but we're still a few months away from April Fools Day. Apparently Nancy Pelosi and her entourage (including Murtha) are off to Iraq. Now had they been going to visit the troops, bolster morale, etc. -then I'd know it was a joke. But no, they're planning on meeting with al-Maliki, the Iraqi prime minister. Now, correct me if I'm wrong (because I know certain Democrats have ignored it before with not so much as a slap on the wrist), but doesn't our Constitution say something about the president being the only one responsible for foreign policy? Meeting with foreign leaders, making agreements, signing treaties, etc. For Congressmen (and women) to pretend to be president undermines our real president's authority. Now, maybe they're just going to have tea with him, I don't know, but this sounds highly sketchy to me... The only theory I have right now is that Pelosi intends to blink al-Maliki into submission about her cut and run strategy.