As North Korea continues its steadily expanding nuclearization, US President Donald Trump will have to prepare for extremely complex crisis diplomacy. Whether he decides upon a path of military preemption (what his lawyers would then call "anticipatory self-defense") or waits for a first move by Pyongyang, Trump will need to (1) make difficult judgments regarding enemy rationality and capability; and (2) consider a prudent posture of "pretended irrationality" for the US. His core task will be to pursue "escalation dominance" without simultaneously exposing the US or its allies to grievous attack.