and those in Biden's and incoming Vice President Kamala Harris's were activated. In February 2021, a group of 31 Congress members signed a letter requesting that President Biden give up sole authority to use the nuclear launch codes. The letter asked Biden "to install checks [and] balances in our nuclear command-and-control structure" and proposed alternatives to the existing structure. The 1986 Goldwater–Nichols Act streamlined the military chain of command, which now runs from the president through the secretary of defense directly to combatant commanders (CCDRs, all four-star generals or admirals), bypassing the service chiefs. The service chiefs were assigned to an advisory role to the president and the secretary of defense and given the responsibility for training and equipping personnel in the unified combatant commands. See also Cheget, the Russian counterpart Continuity of government Emergency Action Message Gold Codes Letters of last resort, the British counterpart Nuclear briefcase Permissive Action Link Roger Fisher, the academic who proposed putting the nuclear codes inside a person so that the US president has to take a life to activate the country's nuclear weapons Two-man rule Notes Further reading Ford, Daniel F. (1985). The Button: The Pentagon's Strategic Command and Control System. New York: Simon and Schuster. . . Gulley, Bill, and Mary Ellen Reese. (1980). Breaking Cover. New York: Simon and Schuster. . . External links Executive Office of the President of the United States American inventions United States nuclear command and control