Here's a top-line summary of all the current news regarding the Kurds. Increasingly aggressive Kurdish guerrillas (i.e. the P.K.K., labeled a terrorist organization by the U.S.) are executing strikes across the Iraqi border into both Turkey and Iran. Because we like Turkey, we are urging the Kurds to stop. But because we hate Iran, we are giving the Kurds advice and possibly direction.
The alternative to tangling ourselves up in microregional conflicts and aligning ourselves with terrorist organizations is to use (gasp!) diplomacy. If we were allowing the P.K.K.'s strikes in Iran to continue because we were using them as a bargaining chip (for example, saying to the Iranians, "In exchange for a concession on your nuclear development program, we will call off the dogs on the Iraqi border.") that would be one thing. But we aren't negotiating in any serious way! Aiding the P.K.K. on its Iranian raids, as the article linked to above strongly suggests we are doing, is apparently intended to destabilize the Iranian regime. The far, far, far more likely result is that it will increase the chance of regional war, keep the Iranians from ever working with us on stabilizing Iraq, and give the Iranians some rhetorical cover when they send Iranian agents into Iraq to attack Americans.
Update: I just want to remind everyone that war with Iran isn't just war with Iran. It means war with Hezbollah, Hamas, and countless hidden terrorist cells across the Middle East, all of which would be unleashed by the Iranian mullahs. Richard Cohen makes this point in a Washington Post op-ed in which he asks Rudy Giuliani to pretty-please consider maybe being possibly less bellicose on the Iranian question.