New York Times:  “American intelligence officials are warning allies that there is a short window of time to prevent Russia from taking military action in Ukraine, pushing European countries to work with the United States to develop a package of economic and military measures to deter Moscow, according to American and European officials.  Russia has not yet decided what it intends to do with the troops it has amassed near Ukraine, American officials said, but the buildup is being taken seriously and the United States is not assuming it is a bluff.

“Avril D. Haines, the director of national intelligence, traveled to Brussels this week to brief NATO ambassadors about American intelligence on the situation and a possible Russian military intervention in Ukraine. Ms. Haines’s trip was long planned and covered a variety issues, but the growing concerns over Russia were among the short-term threats discussed, according to officials briefed on them.

“The United States has also been sharing intelligence with Ukraine. And on Friday, Gen. Mark A. Milley, the chairman of the Joint Chiefs of Staff, spoke with Lt. Gen. Valery Zaluzhny, the commander in chief of Ukraine’s military, to discuss Russia’s ‘concerning activity in the area,’ the Joint Staff said in a statement.  American and British intelligence are increasingly convinced that President Vladimir V. Putin of Russia is considering military action to take control of a larger swath of Ukraine, or to destabilize the country enough to usher in a more pro-Moscow government.”