The Senate Foreign Relations Committee convened on Tuesday for a hearing unlike any in the past 40 years, to discuss and analyze the system used to authorize a nuclear strike that the United States has relied upon for decades.

Chaired by Republican Senator Bob Corker, an outspoken critic of President Trump, the hearing seeks to ask questions about the President’s ability to make war outside the supervision and authorities of Congress. It brings to the forefront a topic that has long troubled those concerned with the scope and limits of presidential power, and particularly those powers which can bring about the end to civilization.

As the realities of the nuclear age, and nuclear-armed superpowers, began to present themselves in the early 1950s, the system by which the United States could order a nuclear response to any threat from the Soviet Union by necessity became more and more consolidated into the hands of a single man: the U.S. president. Nuclear bombs ushered in a new age of warfare, where complete societal annihilation was now not only possible, but likely, in the event that hostilities broke out between the U.S. and the Soviet Union. Not only would the war be all-compassing in its destructive capability, but it could happen quickly, with little to no warning. Through a series of evolutions in America’s strategic defense initiatives, the power to authorize a response, as well as a preemptive attack, coalesced into the hands of whoever occupied the White House. For the duration of the Cold War and the years immediately following it, this system worked. But what happens when a political wild card ascends to the Oval Office?

At this point in modern American culture, few people still stop and reflect on just how closely the United States and Soviet Union came to global nuclear war. As former Secretary of Defense Robert McNamara once said, in a time span of seven years at the height of the Cold War, the U.S. and USSR came within minutes and seconds of launching nuclear weapons at each other on three separate occasions, and were only spared through miraculous instances of restraint on both sides.