A surprise attack on a full superpower with extensive MAD capabilities is quite possibly the most idiotic move that could ever be made. Milley's call can be summed up as: "you know I'm not an idiot, remember?"

Wouldn't a surprise attack, if that was even possible, be the best way to ensure Assured Destruction rather than Mutually Assured Destruction?

All major nuclear powers have systems in place to guarantee the survival of at least some of their strategic nuclear forces in the event of a surprise attack, ballistic missile submarines being one of them.

It would be terrible against a full nuclear triad nation. It’s assumed that the US has nuclear weapons in silos, on airplanes, and in submarines at all times and under certain conditions each silo/plane/sub is capable of making the call to attack.

A surprise attack would only prevent MAD if you were to simultaneously disable each individual silo/sub/plane which is practically impossible.

Oh, and it’s entirely possible the US has classified space based retaliation capabilities as they have had a number of highly classified satellite launches.

Milley said he would warn the Chinese if Trump decided to launch an attack during the presidential transition period. That doesn't mean the US will warn China if it decides to launch an attack in the future.

> That doesn't mean the US will warn China if it decides to launch an attack in the future.

That's just a courtesy call. ICBMs aren't stealthy, and most developed countries will notice when it happens.