On 20 January, inauguration day, a military aide carrying a briefcase known as the 'nuclear football' accompanied President Barack Obama to the handover ceremony. Inside the football was a 3in by 5in device called 'the biscuit', containing the launch codes for a strategic nuclear strike. After Donald Trump took the oath of office, the aide and the satchel moved to his side, giving him sole authority to order a nuclear strike.
Concerns have been raised about Trump's temperament and the safeguards against an impulsive decision. While Trump has rowed back on some provocative comments, stating he would be 'the last person to use them', he has not ruled out their use. Mark Fitzpatrick, a nuclear non-proliferation expert, says there are no checks and balances on the president's authority to launch a strike, though other officials are involved in the chain of command.
The Secretary of Defence could theoretically refuse an order if doubting the president's sanity, but this would be mutiny, and the president could fire him. Under the 25th Amendment, the vice-president could declare the president mentally incapable, but would need a majority of the cabinet. The 'nuclear football' contains a black book of strike options, and the president authenticates his identity using a plastic card.
Once the president selects strike options, the order passes via the chairman of the Joint Chiefs of Staff to the Pentagon's war room, then to US Strategic Command HQ, and finally to launch crews using encrypted codes. As of September 2016, Russia had 1,796 strategic nuclear warheads, the US had 1,367, and the UK had about 120, with only a third deployed at sea.
