“The committee is clearly looking for remedies to ensure that a demented president could not unilaterally start a nuclear conflagration,” said Bruce Blair, an expert on nuclear command and control and a research scholar at the Program of Science and Global Security at Princeton University.

As commander-in-chief, the president has the sole authority to order a nuclear strike. While existing procedures call for the president to consult first with military and civilian leaders, the final decision rests with him.

“No one can veto the president’s decision,” said Blair, co-founder of Global Zero, an international movement for the elimination of nuclear weapons.

Some members of Congress are pushing for a check on the president’s powers.