With the situation on the ground in Ukraine growing increasingly dire, The Circus explores what more the U.S. and its allies can do. As Secretary of State Antony Blinken travels to Estonia, John Heilemann speaks with Prime Minister Kaja Kallas about fears Putin could strike a NATO nation next. Plus, Mark McKinnon explores President Biden's response with Senator Mitt Romney; Alex Wagner interviews Ukrainian parliament member Oleksandra Ustinova; and Jennifer Palmieri speaks with officials about the threat Putin now poses to the world.

As President Biden travels to Brussels for an emergency NATO summit, The Circus examines Russia's threats of using nuclear weapons. Jennifer Palmieri speaks to Pentagon Press Secretary John Kirby about the U.S. response to Putin's nuclear saber-rattling; John Heilemann games out war simulations with one of the world's foremost experts on nuclear weapons, Zia Mian; and Alex Wagner assesses Putin's motives with former Russian Foreign Minister Andrei Kozyrev.