Decision-making process of US president revealed in account based on information from over a dozen legislators, congressional aides, administration officials

US president says no preconditions for talks with Tehran but won't allow them to have nuclear weapons; US military was 'cocked and loaded' to retaliate for downing of drone

Democrats have derided the administration for an incoherent strategy they say is escalating tensions. But the president's allies insist everything is going exactly as planned

Overtures for talks by Trump have little chance of yielding results, putting countries on potentially disastrous collision course, though some see peaceful ways out of standoff

Britain, France, Germany, China, Russia and Iran to convene June 28 in Vienna in bid to stem unraveling of 2015 accord, amid rising tensions between Tehran and Washington

Former VP and presidential hopeful says it 'sadly ironic' that State Department 'now calling on Iran to abide by the very deal the administration abandoned'

Heiko Maas says Berlin talking to all sides in bid to calm tensions between US and Iran after tanker attacks, troop buildup

Officer says parts from unexploded mine used to attack ships last week similar to bomb made by firm linked to Revolutionary Guards

In Washington, Mogherini tells Pompeo the union views survival of Iran nuclear deal as 'key to preserving stability and security in the region'

Israeli, Western intelligence officials said to warn that Tehran is frustrated at failure to force Washington to negotiation table