1. Congress did this to undermine the Iraq war effort. In knowing full well what Turkey would do, they thought it would be cute if supplies to the troops were cut off, and if the Kurdish province was destablized as a bonus. I'm surry Nancy, Harry and co. are quite pleased over the notion of Turkey invading Iraq and pushing the region into a state of chaos.
2. The Russians are more certainly happy. Why? Turkey is a major pipeline hub for oil and natural gas. Now that our Congress is pissed 'em off, the Turkish government will be anxious to cut off as many contracts as possible with companies that have US interests, and in turn favor Russia's Gazprom for new contracts. With Turkey piping in Russian oil, Russia has lock-stock control of the EU over energy issues.