While the U.S. Air Force Global Strike Command conducted a test on Aug. 4 of an unarmed LGM-30G Minuteman III ICBM with three test reentry vehicles, such tests with dummy, Multiple Independently-targetable Reentry Vehicles (MIRV) are uncommon.

There appear to have been just three MIRV ICBM tests since 2017, including one on Feb. 8 that year, less than a month after President Trump assumed office; one on Apr. 25, 2018 just days before a planned summit between North Korea and South Korea; and the Aug. 4, 2020 test. The Air Force typically conducts unarmed ICBM tests three to five times per year.

While China has MIRVs on its ICBMs, and Russia has MIRVed ICBMs and submarine launched ballistic missiles (SLBMs), the U.S. deploys MIRVs only on SLBMs.

“Since the United States does not MIRV its ICBMs, showing that it [the Aug. 4 test] is part of a standard pattern could allay any concerns that the United States was trying to send a message,” Geoff Wilson, a policy analyst with the Center for Arms Control and Non-Proliferation, wrote in an email. “At the same time, there are not prohibitions on MIRVing missiles under New START. The treaty limits the total amount of warheads that can be placed on a set number of deployed launchers. START II, negotiated by the administration of former President George H.W. Bush, did prohibit MIRVing on ICBMs, but that treaty never entered into force.”

New START caps the number of deployed strategic nuclear warheads and bombs at 1,550, down from the 2,200 limit imposed by the 2002 Strategic Offensive Reductions Treaty (SORT)—the so-called Moscow Treaty, and the 6,000 limit under the 1991 START agreement.

“Unfortunately while we continue to push ahead with testing and modernizing our forces to the tune of $1.7 trillion over the next 30 years, we have made no steps towards negotiating any new strategic arms control treaties under this administration,” Wilson wrote. “As it stands, President Trump will soon be the first president since Kennedy not to negotiate an arms control treaty with the Russians, and has pulled us out of several important nuclear treaties negotiated by presidents of both parties.”

Wilson said that a proliferation danger lurks in the wake of the Aug. 4 test and in the absence of a new arms control treaty.

“I think this test shows a dangerous potentiality, where if we don’t extend New START, which expires in 2021, we could see a massive redeployment of U.S. and Russian nuclear forces during a period of global instability,” he wrote. “If New START is allowed to expire, both Russia and the United States have the capacity right now to increase the weapons on the launchers by several hundred warheads.”

The Aug. 4 test featured a joint team of Air Force Global Strike Command and U.S. Navy personnel who launched the unarmed Minuteman III from Vandenberg, AFB, Calif. at 12:21 a.m. Pacific Time Aug. 4. Members of the Air Force’s 625th Strategic Operations Squadron, based at Offutt Air Force Base, Neb., were aboard the Airborne Launch Control System (ALCS), a Navy E-6 aircraft by Boeing [BA], to launched the test warheads.

The Air Force’s Vandenberg-based 567th Flight Test Squadron also supported the launch, standing in for the 90th Missile Wing, members of which were not permitted to travel to California from F.E. Warren Air Force Base in Wyoming due to “current COVID-19 travel restrictions,” the service stated.

After the Obama administration’s 2010 Nuclear Posture Review, the United States began de-MIRVing its Minuteman IIIs, which can carry multiple W78 warheads. In June, 2014, Air Force personnel at Malmstrom AFB, Mont., removed the last MIRVs on a Minuteman missile in the 341st Missile Wing’s inventory.

The Air Force would be free to deploy MIRVs on its 400 Minuteman IIIs, if the U.S. Russia New START Treaty, enacted in February 2011, lapses after February next year. To prevent that, the U.S. and Russian presidents must agree to a five-year extension before then.

The Aug. 4 launch took place the same week that Marshall Billingslea — whose nomination as undersecretary of state for arms control and international security the Senate Foreign Relations Committee approved last week on a razor-thin party-line without the support of all 12 Republicans — posted photos of Air Force service members loading up a Minuteman III payload bus with multiple reentry vehicles.

The Air Force plans to replace the 400-missile Minuteman III fleet starting in 2020 with Ground Based Strategic Deterrent Missiles tipped with W87-0 and W87-1 warheads.

Northrop Grumman [NOC] expects the Air Force to award it a $10-billion to $15-billion Ground Based Strategic Deterrent Engineering and Manufacturing Development contract this month. Under that deal, Northrop Grumman would develop, manufacture and eventually deploy up to 650 new missiles.