A group of 17 former nuclear launch officers is warning that President Trump has put the U.S. on a collision course with North Korea and is asking Congress to rein in his ability to conduct a nuclear first strike.

The warning was made in an undated open letter to lawmakers this month organized by the group Global Zero, which advocates for the elimination of nuclear weapons, and is the latest outcry from Trump critics over the way the president is handling the growing threat of a nuclear North Korea.

“We and our nation cannot abide being hostages to the mood swings of a petulant and foolish commander-in-chief. No individual, especially Donald Trump, should hold the absolute power to destroy nations,” wrote the former officers, who all oversaw nuclear weapons at U.S Air Force bases and whose service ranged from 1965 to 2013.

Trump has most recently been weighing a “bloody nose” strategy that would include a limited strike on regime leader Kim Jong Un’s nuclear program as the U.S. waits to see whether new sanctions and economic pressure will bring the North Koreans to the negotiating table.

The North has pressed on with its quest to obtain nuclear weapons for years through testing and launches despite outcry from the U.S. and the international community. During Trump’s first year in office, it tested intercontinental ballistic missiles that could be capable of dropping a nuclear warhead on American cities.

Time and again, Trump has sparred verbally with the regime, promising “fire and fury" in a U.S. response, calling Kim “little rocket man” before the United Nations, and claiming his nuclear “button” is bigger than the North Korean leader’s.

“Every one of these episodes points to a flaw in the nuclear launch process that poses a clear and present danger to the country and the world: Every American president has absolute authority to order the first use of nuclear weapons,” the officers wrote in the open letter. “No one — not the secretary of defense, not the attorney general, not Congress — can veto that order. There are no reliable safeguards in place to contain this power.”

The letter does not recommend any particular new legislation. Democrats in the House and Senate have introduced bills that would restrict the president’s ability to launch a nuclear first strike unless authorized by Congress.

“Any of these common-sense measures would reduce the risk we now face. All are backed by top experts and worthy of consideration,” they wrote.