The U.S. Air Force is handing over NATO air-policing duties for Poland and the Baltics to a multinational force comprised of Polish, British, Danish, and French fighter aircraft. The scheduled transfer is part of NATO collective defense measures that were agreed upon by the allies early in April. The goal is to reassure allies in Central and Eastern Europe.

“This, alongside the other action we are taking, will provide reassurance to our NATO allies in Eastern Europe and the Baltic states,”

The formal transfer will take place on May 1. The United States had responsibility for air-policing from Jan. 1 to April 30. The mission will be led by four MiG-29 Fulcrums from the Polish Air Force. They will replace 10 U.S. Air Force F-15C Eagles. Backing up the MiG-29s will be a four-ship detachment of Royal Air Force (RAF) Typhoons. “As a leading member of NATO, the U.K. is playing a central role, underlined by today’s deployment of RAF Typhoon aircraft to Lithuania. This, alongside the other action we are taking, will provide reassurance to our NATO allies in Eastern Europe and the Baltic states,” British Defense Secretary Philip Hammond said in an RAF statement. The Typhoons will operate out of Siauliai Air Base in Lithuania. The Typhoon deployment comes six weeks after a U.K. E-3D Sentry AWACS (Airborne Early Warning and Control Aircraft), which is part of the NATO E-3A component, started covering Polish and Romanian airspace from its base in Waddington, U.K.

In Estonia, Royal Danish Air Force F-16 Fighting Falcons will be fly out of Amari Air Base, and four Armée de l’Air Dassault Rafales will be stationed at Malbork Air Base in Poland. As part of a previously announced commitment, six Royal Canadian Air Force CF-18 Hornets departed Canada on April 29 for deployment to Romania. The four nation air-policing effort will last through August.

“We cannot continue to allow allied defense budgets to shrink. Clearly, not all allies are going to meet the NATO benchmark of 2 percent of GDP overnight or even next year. But it’s time for allies who are below that level to make credible commitments to increase their spending on defense over the next five years.”

Estonia, Latvia, and Lithuania do not have fighter aircraft of their own and so rely on four-month rotations of NATO fighter aircraft to ensure the sovereignty of their airspace. This lack of fighter aircraft has been magnified amid calls for increased defense spending among NATO allies. During a speech at the Atlantic Council in Washington, D.C. on April 29, Secretary of State John Kerry urged increased defense spending among members of NATO. “We cannot continue to allow allied defense budgets to shrink. Clearly, not all allies are going to meet the NATO benchmark of 2 percent of GDP overnight or even next year.  And if we’re going to move the trend line in a positive direction, this has to be an alliance wide effort.”

Although NATO members have taken turns deploying fighter aircraft to police the airspace of Poland and the Baltics for the past 10 years, this effort has intensified with the situation in Ukraine. The air-policing is usually composed of four-ship detachments, but these have been reinforced due to the crisis.