The US is sending Europe a warning about an agreement that lets them keep an eye on Russia

US Air Force/Josh Plueger The Trump administration has told European allies that the US will likely abandon the Open Skies Treaty unless they can address concerns about the pact. The US believes that Russian violations of the treaty, which allows signatories to conduct observation flights over other signatories' territory, as well as other technology make it obsolete. Visit Business Insider's homepage for more stories. WASHINGTON — NATO allies worried US President Donald Trump will abandon the...