Russian President Vladimir Putin’s military forces are ready to conduct an assault on Ukraine at any moment, according to U.S. lawmakers and observers, and his choice of target could expose a deep rift within NATO and the European Union.

“From my understanding, they are likely pretty close to what they need,” Senate Foreign Relations Chairman Bob Menendez told the Washington Examiner this week. “They have a very good foundation for what they might want to do. I’m not saying that it’s absolute yet, but it’s a very good foundation.”