Ukrainian President Volodymyr Zelenskyy; House Speaker Mike Johnson.

Roundtable: former New Jersey Governor Chris Christie, former DNC chair Donna Brazile, and former RNC chair and Trump White House chief of staff, Reince Priebus.

Vice President JD Vance said Sunday that despite the U.S. strikes on Iran's nuclear sites last night, the U.S. is not at war with Iran. Tom Cotton the chair of the Senate Intelligence Committee said Sunday that the United States must "be prepared for Iran to retaliate" following Saturday night's strikes targeting three Iranian nuclear facilities. Rep. Jim Himes, the ranking Democrat on the House Intelligence Committee, said it was too early to know the success of a series of U.S. attacks against Iran -- calling the strikes a "massive gamble" on the part of President Donald Trump and citing past U.S. military action in the region.

To help us understand the fallout in the U.S. and in the Middle East from President Trump's action against Iran, I'm joined now by ABC News contributor and former New Jersey Governor Chris Christie and Iran expert Karim Sadjadpour of the Carnegie Endowment for International Peace.