Is Iran seeking to reduce tension with U.S. in Iraq?

TEHRAN (Reuters) - Iran is defiant in a row with the West over its disputed atomic plans but may be seeking to ease tension with the United States by trying to restrain Shi'ite militias in Iraq and restricting arms crossing the border. 

U.S. officials, who accuse predominantly Shi'ite Muslim Iran of stirring up instability in its neighbour, appear to have softened their language in the past few weeks and pointed to a decline in attacks in Iraq by groups using Iranian munitions.