- guardian.co.uk, Sunday 17 October 2010 21.09 BST
Undertaking or supporting an attack upon Iran would simply be much harder for Iraqi politicians who relied upon Iran for protection during the last three decades of Ba'athist rule and who often made common cause with the Tehran against the Iraqi military. This is one reason why Iran has supported its Iraqi allies in their ongoing de-Ba'athification efforts and why it would prefer not to see a new, cross-sectarian nationalist bloc emerge in Iraq.
Looking forward, Iran's supporters in the Iraqi government will seek to complicate the task of negotiating a post-2011 US-Iraqi security agreement and to restrict the scale and effectiveness of American security assistance to Iraq's external security forces. Though Iranian-backed militancy in Iraq is an irritant in the two countries' relations, the al-Quds Brigades of Iran's Revolutionary Guard Corps (IRGC), responsible for operations outside Iran, will maintain its ability to target US military personnel, diplomats and private citizens in Iraq, which could act as one source of deterrence against a US or Israeli military strike on Iran - a nightmare scenario for US generals and diplomats in Iraq.
Michael Knights is a Lafer fellow at the Washington Institute for Near East Policy, specialising in the military and security affairs of Iraq, Iran, Yemen, and the Gulf Arab states.