The potential concession would test the limits of longstanding US demands that Iran’s nuclear program not leave any possible path to a bomb.

The gambit was successful. At least twice, the president weighed ordering an attack on Iran, only to be dissuaded by aides from moving forward. But America now appears to be on the brink of war with Iran again. And this time, instead of acting as a deterrent, the Pentagon’s war plans are being used to draw up options for the president to consider.

As the United States continues a significant military buildup in the Middle East, Iran has taken steps to signal its readiness for war, including fortifying its nuclear sites and rebuilding missile production facilities.

Iran and the United States are waging gunboat diplomacy as talks over Tehran’s nuclear program hang in the balance.

The Iranian naval drill and the arrival of the USS Gerald R. Ford aircraft carrier near the mouth of the Mediterranean Sea underscore the tensions between the nations.

Iran and the United States are sliding rapidly towards military conflict as hopes fade for a diplomatic solution to their standoff over Tehran’s nuclear programme, officials on both sides and diplomats across the Gulf and Europe say.

President Donald Trump’s choice on Iran amounts to this: He can either enforce his red line — however belatedly — or do something quite politically fraught.

Add Yahoo as a preferred source to see more of our stories on Google. FILE - In this photo released by the Iranian Foreign Ministry, Iranian Foreign Minister Abbas Araghchi, left, is welcomed by an unidentified Omani official, center, upon his arrival at ...

President Trump has one bright red line for Iran's nuclear program and some areas of flexibility as he weighs military strikes or a possible deal in the coming days.