A group of scientists proposed a plan Wednesday that would limit presidential authority to unilaterally order a nuclear attack.

The plan would require that the president first obtain approval from the next two officials in the presidential succession chain — the vice president and speaker of the House, according to a paper in the Bulletin of the Atomic Scientists, a global disarmament advocacy.

As commander in chief, the U.S. president currently has the authority to order the U.S. military to launch nuclear missiles.

The release of the paper follows President Donald Trump recently boasting about his "nuclear button" being "much bigger and more powerful" than the North Korean leader.

Back in November, there was discussion in the Senate Foreign Relations Committee about limiting the president's nuclear strike authority after some Democratic lawmakers cited Trump's "unstable" behavior.

"No one person should be able to order a nuclear attack," said paper co-author Lisbeth Gronlund, a senior scientist and co-director of the Global Security Program at the Union of Concerned Scientists (UCS). "There's no reason to maintain this dangerous policy, since there are viable alternatives that would allow other officials to take part in any decision to use nuclear weapons, whether it's a first use or a launch responding to a nuclear attack."

According to the paper, "the risks are not hypothetical. During the Watergate scandal, President [Richard] Nixon was drinking heavily and many advisers considered him unstable. During the 1974 impeachment hearings, Nixon told reporters that 'I can go back into my office and pick up the telephone and in 25 minutes 70 million people will be dead.'"

The paper was co-authored by David Wright, a UCS senior scientist, and University of Maryland professor Steve Fetter.

The authors of the paper said the "proposal applies to any use of nuclear weapons, regardless of whether it would be the first use of nuclear weapons or in response to a nuclear attack or warning of an attack."

Michaela Dodge, a policy analyst specializing in nuclear weapons policy at the conservative think tank Heritage Foundation, said deterrence is a key part of the U.S. nuclear program and the ability to respond rapidly to threats.

"One of those requirements that is critical for deterrence is to be able to have an authority to respond quickly," Dodge said. "That authority lies solely with commander in chief, and I'm very comfortable with that."

Changing the current procedure for ordering a nuclear strike could add several layers of "negative security effects," she said.

The Heritage analyst also said there are other people who have influence on the decision of presidents to order a nuclear strike.

At the same time, military generals can essentially refuse to follow what they consider "illegal orders," retired Gen. Robert Kehler testified at the Senate Foreign Relations Committee hearing in November. Kehler is the former commander of the U.S. Strategic Command.