The US Senate Foreign Relations Committee Tuesday held the first congressional hearing in over four decades on the constitutional issues surrounding the US president’s authority over and the concrete procedures involved in the launching of a nuclear war.

The discussion unfolded as three nuclear-powered US aircraft carriers have been deployed off the Korean Peninsula provoking a protest from North Korea that they are engaged in “nuclear war exercises” that threaten “international peace and security.”

Clearly prompting the hearing was the increasingly tense situation on the Korean peninsula and the bellicose threat made by President Donald Trump to unleash “fire and fury like the world has never seen” in response to North Korean “threats,” as well as his speech before the United Nations General Assembly in September vowing to “totally destroy North Korea” and its 25 million inhabitants.

The chair of the committee, Republican Senator Bob Corker of Tennessee, has been openly critical of Trump’s policy, describing the White House as having been turned into an “adult day care center” and warning that the president’s threats were leading the United States “on the path to World War III.”

These warnings were echoed by Democratic members of the Senate committee in Tuesday’s hearing. Massachusetts Senator Ed Markey, for example, warned that there “could be plans in place right now in the White House given to the president to launch a preemptive war against North Korea using American nuclear weapons without consulting with, informing Congress whatsoever by arrogating that power to the executive branch in clear violation of the Constitution.”

Senator Chris Murphy of Connecticut added, “We are concerned that the president is so unstable, is so volatile, has a decision-making process that is so quixotic, that he might order a nuclear-weapons strike that is wildly out of step with US national-security interests.”

In the end, however, the hearing provided a revealing glimpse of congressional impotence and the support of both major parties for the “modernization” of US imperialism’s nuclear arsenal in preparation for a Third World War.

Testifying before the panel was the former head of the US Strategic Command, which oversees the US nuclear war machine, retired Air Force Gen. Robert Kehler. He was joined by a former Defense Department official under the Obama administration, Brian McKeon, and a former member of the National Security Council under George W. Bush, Peter Feaver.

General Kehler provided the most significant testimony, leading off with a statement on the “paradox” of nuclear weapons that could have been lifted from the script of Dr. Strangelove: “In order to prevent their use we have to be prepared to use them.”

He warned Congress against passing legislation changing the current system governing nuclear war or limiting the powers of the US president to launch one.

Any attempt to “presuppose all of the scenarios under which we would somehow want to limit the powers of the commander-in-chief” would be to a “detriment to the overall deterrent” and would have detrimental “implications for our own military men and women and the confidence they place in the chain of command.”

He said that the regime currently in place within the US nuclear command “accounts for the potential for the kind of scenarios we have been talking about today,” including the launching of a nuclear first strike “before an adversary weapon has been used.”

General Kehler told the panel that US military commanders could refuse a presidential order to carry out a nuclear first strike if they considered it against the laws of war in terms of military necessity and proportionality.

“If an illegal order is presented to the military,” he said, “the military is obligated to refuse to follow it,” he said, insisting that this was the standard upheld by the Pentagon in relation to every action, not just nuclear war. Of course, the credibility of this assertion is undermined by the American military’s involvement in countless war crimes from torture to massacres of civilians, use of chemical weapons and the wholesale bombing of the populations of Iraq, Afghanistan, Libya, Syria and Yemen.

In the event of an unjustified order for a first strike, the general continued, the military commanders would advise the president against nuclear aggression “Action can be taken if the president overrules that and says we’re going forward with an attack,” the general continued.

Such action by the military brass, he added, would pose a “very interesting constitutional situation,” suggesting the distinct possibility of the military seizing power.

The general’s testimony drew a sharp rebuke from two Republican senators. Marco Rubio of Florida warned against “bunker lawyers who decide that they are going to disobey any order they disagree with” leading to a situation that could “spin out of control.”

Senator James Risch of Idaho warned the panel that “Pyongyang is listening” and that no one should say anything to undermine Trump’s threats of nuclear annihilation.

“Every time the president has used force, he has had the support of the Congress and the American people,” Risch said. He stated that the US Constitution was “written in a different time” and that the speed of developments today precluded observance of its provision giving Congress the sole authorization to declare war.

“Decisions have to be made in a matter of minutes, and they won’t be made by lawyers, by courts or by Congress,” he said. “They are going to be made by the commander-in-chief,” adding that Trump “will do what is necessary to defend this country.”

McKeon, the former Pentagon official from the Obama administration, allowed that he was “very worried about a miscalculation based on the continuing use of his [Trump’s] Twitter account with regard to North Korea.”

He added, however, “Hard cases make bad law. If we were to change the decision-making process in some way because of distrust of this president it would set an unfortunate precedent for future presidents.”

Feaver, the Bush-era National Security Council official, suggested that the main aim of Congress should be to “reassure the American public that they have a nuclear arsenal that is well maintained and well guarded against unauthorized use.” He suggested that the Senate’s going ahead with a debate on the issue and then deciding “not to make a legislative fix” would “go some distance toward reassuring the public.”

Corker, who has close ties to the military, summed up the hearing by declaring that he didn’t “see any legislative changes as it relates to the power of commander-in-chief” and calling for the modernization of US nuclear weapons to “make sure that if they are called upon to be used they will actually do the things that they’re intended to do.”

Senator Markey spoke at the close of the hearing in opposition to “trusting the generals to be a check on the president” and insisting that in the case of a preemptive nuclear war Congress had to provide authorization. He complained, however, “An atmosphere of ambiguity has been created by president after president around whether or not they are going to defer to our authority.”

The reality is that Congress long ago surrendered its war powers under the Constitution with war after war being waged with no congressional declaration of war, and ever-spreading and unending military interventions being conducted in open breach of the War Powers Act, passed in 1973, requiring congressional authorization for any military action lasting more than 60 days.

While ostensibly inspired by concerns over a politically unstable US president launching an unprovoked nuclear first strike, Tuesday’s hearings only underscored the instability of the entire system which is driving US imperialism toward a third world war abroad and dictatorship at home.