Although tensions between the United States and Russia have increased in recent years due in large part to Russian disinformation and espionage operations the world over, these two nations still maintain a number of security-centric treaties meant to diffuse the possibility of open war. Some of these treaties have been very publicly tossed aside in recent months, but others, like the 1992 Open Skies Treaty, remain an active (and often contested) part of America’s tumultuous relationship with Putin’s Russia.

The Open Skies Treaty is an agreement established between 34 signatory nations that allows for unarmed and observed military surveillance flights over one another’s nations. In short, it grants these nations stipulated permissions to fly spy planes through one another’s airspace to keep track of various elements of any nation’s military apparatus. Russia and the United States, both signatory members of the treaty, use this agreement to fly their reconnaissance aircraft over areas of strategic interest, but those flights must come with prior approval from the host nation and usually include local observers flying on board the surveillance flights. Strict regulations are meant to ensure only certain types of intelligence are gathered, and the local observers ensure these flights abide by the terms that have been agreed to ahead of time.

Russian Tu-154 (WikiMedia Commons)

In 2017, for instance, a Russian Tu-154 was spotted by nervous spectators flying as low as 3,700 feet over Washington D.C., gathering intelligence data for the Kremlin. Soon thereafter, however, Russia attempted to curtail America’s planned Open Skies flights, resulting in months of diplomatic squabbling.

Last week, for the first time since 2017, a Russian Tu-154 was once again spotted operating over the American mainland thanks to the Open Skies Treaty, but rather than flying over the nation’s capital and Camp David as they have in the past, these flights included areas of unusual interest, such as a small airstrip in the Groom Lake Dry Bed nestled in the Air Force’s Nevada Test and Training Range. That airstrip and its associated facilities are better known colloquially as Area 51.