Although administration officials hope diplomatic efforts to restrain Iran will succeed, "it is not in their nature to bequeath the problem to their successors", a senior White House source told the Sunday Times of London last week.
The Sunday Times said the Pentagon is believed to be considering options that would allow it to destroy facilities such as Iran's main centrifuge plant at Natanz in a single night of bombing.
A report by Seymour Hersh in this week's New Yorker magazine claims the Pentagon is also considering the use of a tactical nuclear weapon, the Sunday Times reported.
The Washington Post said it appears unlikely that there would be an attack in the short term. The newspaper said many specialists inside and outside the U.S. government doubt an armed response would be effective.
They warn that a strike at Iran would just delay its nuclear program by a few years but could inflame international opinion against the United States and make U.S. troops in Iraq targets for retaliation.