US delays Minuteman ICBM test launch to calm nuclear tensions. How do ICBMs work?

Like other inter-continental ballistic missiles, the Minuteman has three-stage rocket motors and is fuelled by solid propellant. In its second stage, the missile is practically in space and then makes a re-entry into the Earth's atmosphere and uses its rocket booster to orient itself towards the target. 

Ever since the production of the missiles stopped in 1978, the U.S. military has been running modernization programs for the missiles that have seen the rocket stages being upgraded, expansion of target options and improvements in accuracy and survivability, the U.S. Air Force website said. 

Scheduled Periodic Tests

To verify that the programs are delivering the intended results, the U.S. military periodically tests the Minutemen missiles, of which it has 400 in stock. An unarmed missile is fired from the Vandenberg Space Force Base in California and completes a 4,200-mile arc to hit the target in a test range at the Kwajalein Atoll in the Marshall Islands like the one U.S. Space Force tested in 2020. 

Although many countries now possess ICBMs, none have actually been fired in combat to date.  Pentagon spokesperson John Kirby said that the U.S. delay in testing its weapon was to signal to Russia that it had "no intentions of engaging in any actions that could be misunderstood," rather demonstrating that the U.S. was a responsible nuclear power. 

Even as the Russian attack on Ukrainian cities has been indiscriminate, the country has demonstrated restraint by not launching strategic bomber flights, Rose Gottemoeller, a retired U.S. diplomat and former deputy secretary-general of NATO told Time. As the Russian invasion is bogged down further by the stiff resistance put by Ukraine, the risk of a nuclear war is higher. The U.S. decision to delay its launch is expected to simmer the tensions a bit.