Iran has denied supporting the rebels, though it has defended them in public statements, accusing the Saudis of "fratricide" for fighting and killing Houthi rebels. The U.S. has said it has no independent evidence proving an Iranian link to the Houthis, but has supported Yemeni authorities against what it described as an armed insurgency.
Petraeus says he does worry about Yemen as the next potential hotbed of militancy. One of the poorest states in the region, Yemen is home to the headquarters of Al Qaeda in the Arabian Peninsula and run by a weak central government.
"There's tribal elements, discontent in some areas, a lack of basic services, and a very rugged terrain that Al Qaeda has found conducive to its operations in the border areas of Pakistan," Petraeus told ABC News.
His overall message on the Iraq war was that violence is down, and that the withdrawal of U.S. troops remains on track. The postponed Iraqi elections, he said, would only speed up the drawdown. He described how the strategy credited with calming the violence in Iraq, one which involved working with local tribes to foster more capable self-defense at the local level, would be replicated in Afghanistan.
"Is there potential for this? We think so. We have launched initiatives to test that proposition," he said. Part of the approach involves a margin of forgiveness and reconciliation, allowing low- and mid-level Taliban fighters to put down their arms and re-enter society under the current government.
"There have actually been in the past few months several reasonably significant cases of Taliban elements literally coming in with their hands up," he said, adding that the "true irreconcilables have to be killed or captured."