India, Sept. 15 -- Eight decades ago, US President Harry S Truman faced a decision that would change the nature of warfare forever.

Japan was still fighting after the surrender of Nazi Germany. The US possessed a weapon unlike anything the world had seen. Truman and his advisers had to decide how best to use America's overwhelming military power to end the war.

Today, Donald Trump faces a different problem. Iran has suffered substantial military damage, but military success has not translated into the decisive political outcome the US seeks.

Japan in 1945 and Iran today are fundamentally different cases. Nor can the atomic bomb of 1945 simply be compared with today's sophisticated nuclear arsenals.

Yet, there is a common strategic pro...