Panetta claims Iran is supporting Shia militias in Iraq

The US is a rapidly declining influence in Iraq, but a failure to coerce the Iraqi government to request an extension of the troop agreement would be a humiliation.

The recent attacks on American soldiers which have spiked recently probably are meant mostly to pressure Iraq's civilian leaders to resist pressure from the US Embassy and from Iraqi military leaders who are part of US chains of command. The US is probably a secondary target. Possibly deaths of US soldiers may remind US politicians of the continuous losses in Iraq that did not have an explanation that would satisfy US voters.

Defense Secretary Leon E. Panetta said Sunday that weapons supplied by Iran are behind a rash of attacks against American forces in Iraq, part of an escalating campaign of violence ahead of the planned U.S. troop withdrawal by the end of the year.

"We're seeing more of those weapons going in from Iran, and they've really hurt us," said Panetta, who arrived in Baghdad on an unannounced visit after a two-day stop in Afghanistan.

It is easily possible that Iraqi parties that want the US to leave are able to get arms from Iran. Some of their arms ultimately come from China and Russia, Iraqis who want the US to leave have resources and can buy arms on the market.

Of course, if US troops leave Iraq, Iran and everybody else will be unable to supply Iraqis with weapons to kill US troops.