Well considering that the US nuclear launch codes were just zeros for a while, it just might be realistic.
Unless someone sends the suit with the codes in it to the Chinese dry cleaners…again…and again.
Launch codes aren’t to block China from authorizing a launch. They’re there to keep someone in the military from doing a launch without authorization. China is probably one of the parties who least wants said codes leaking.
If you have a couple hundred people who can start a nuclear war, that war becomes a whole lot more likely than if only one can.
From China’s standpoint, the next best number of people who can launch against them after 0 is 1.
The British used bicycle keys on their nuclear bombs.
http://news.bbc.co.uk/2/hi/7097101.stm
As people learned around that time, a really great way to bypass bicycle locks is with a ballpoint pen.
https://www.wired.com/2004/09/twist-a-pen-open-a-lock/
That was aimed more at keeping honest people honest.