The Russian government banned, April 14, 2014, the overflight of its territory by a U.S. spy plane under the Treaty on Open Skies.

Since 1992, the states party to the treaty - which are currently 34 and include members of NATO and the former Warsaw Pact - have routinely authorized the overflight of each other’s surveillance planes to observe the movements of their respective military forces.

The U.S. Joint Chiefs of Staff suspect that Russia is preparing an invasion of Ukraine and has interpreted this unexpected ban as a dissimulation attempt.

In retaliation, the U.S. National Security Council is thinking of denying overflight rights to the new Russian spy plane, Tupolev Tu 214ON .

However, even before this situation, U.S. lawmakers (including the Chairman of the Intelligence Committee of the House of Representatives) had cried out against the performance capabilities of the Tu-214ON and asked the Pentagon to prohibit its missions over national territory. It would seem, in fact, that Russian sensors are now technically far superior those in NATO’s hands.

In their letter to John Kerry, four Congress members (Dan Coats, 
Mark W. Warner
, James E. Risch and Martin Heinrich) stated that the problems related to Crimea are a sufficient pretext to warrant the ban.