U.S. PLANS INCLUDE FULL ATTACK - TWO POSSIBLE TRIGGERS

"US contingency plans for air strikes on Iran extend beyond nuclear sites and include most of the country's military infrastructure... the trigger for such an attack reportedly includes any confirmation that Iran was developing a nuclear weapon... (or) a high-casualty attack on US forces in neighbouring Iraq could also trigger a bombing campaign if it were traced directly back to Tehran..."
http://news.bbc.co.uk/2/hi/middle_east/6376639.stm