Military planners are advising President Trump that any strike on Tehran's assets would almost certainly not be a singular, decisive blow.

Iran agreed a secret €500mn arms deal with Russia to acquire thousands of advanced shoulder-fired missiles in its most significant effort to rebuild air defences shattered during last year’s war with Israel.

Secretary of State Marco Rubio is traveling to the Caribbean country of St. Kitts and Nevis this week to reassert the Trump administration’s interests in the Western Hemisphere.

Tehran and Mashhad universities saw anti-government protests Sunday, with students chanting against Ali Khamenei as security forces reportedly used tear gas.

"There are capabilities Iran did not fully employ in the previous round," a former senior Israeli military analyst told Newsweek.

Lebanon has been the site of numerous Iran-related retaliatory attacks against U.S. facilities, interests and personnel for decades given Tehran's support for and influence with the Hezbollah militant group.

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.

Iranian university students chanted anti-regime slogans in Tehran on Monday as nuclear talks with the U.S. and Iran are expected to resume on Thursday.