Upon determining just exactly who is responsible, to include those on the ends of the telephone conversations indicating their involvement, the group leadership that immediately claimed the downing then as quickly removed that claim, and anyone remotely involved in the decision to fire that Missile should all be visited by the B-2 folks with a full Fleet Operation until we whack everyone involved.
If Putin makes so much as a peep then we put into place Economic Sanctions that will force his own Military to remove him....permanently.
But as we have Welfare Man at the Helm, about all we shall hear is some half witted comments and token sanctions on Russia that are meaningless.
The Europeans will wring their hands, and do nothing as well.