"Lawful"?

From RT.com:

The partially censored document cited a failure to take "all lawful actions necessary to immediately regain control of nuclear weapons," without specifying those actions. The scenario, under which a hostile force, possibly terrorist, would seize a nuclear missile silo aiming to capture the missile warhead is called ‘Empty Quiver’, and the internal report said the security team demonstrated called a "critical deficiency," in failing to properly respond to it.[italics original]

when it comes to regaining control of nuclear weapons exactly what is the point of "lawful"? When it comes to securing a weapon that can wipe out life for a few miles, I would think that shoot first and don't even consider asking a question would be the only rule in play.