america s closest allies, defense secretary lloyd austin said they must move together at the speed of war to help defend ukraine. we don t have any time to waste. the briefings today laid out clearly why the coming weeks will be so crucial for ukraine. reporter: in an exclusive interview with cnn the chairman of the joint chiefs of staff general mark milley told me the stakes of the war in ukraine are global. if this was left to stand, if there is no answer to this aggression, if russia gets away with this cost-free, then so goes the so-called international order. and if that happens, then we re heading into an era of seriously increased instability. reporter: i pressed general milley on whether the u.s. and nato intended to weaken russia in addition to defending ukraine, as defense secretary austin said monday. has the u.s. aim in this conflict expanded beyond just helping ukraine defend itself to an aim of degrading russia s