The International Criminal Court (ICC) is who the world turns to for justice when a nation won't prosecute it's own people for atrocities such as genocide, war crimes, crimes of aggression, and crimes against humanity.
Trump is rejecting a declaration of war saying, "We're just going to kill the people bringing drugs into our country." "We're going to kill them. So they're going to be, like, dead."
Because of our huge military industrial complex generating millions of dollars for our politicians, our government seems to think the solution to every conflict is spending lots of blood and treasure.