I believe you meant "war is the failure of diplomacy" or as Carl von Clausewitz said "War is the continuation of politics by other means."

The escalation of tensions by the USA against NK is a proxy for the USA's battle in trade, currency and geopolitical influence with China and nothing more. Just like the coup in Ukraine was an action against Russian influence. 

Don't concern yourself with Trump, he is simply reading the script that the MIC provided.