> Why would the US launch an ICBM from within it's borders when it can launch shorter range ballistic missiles from nearly anywhere in the world?
In principle, accuracy: the depressed trajectories you're thinking of tend not to be the most accurate. If you happen to NOT be fighting a full-on nuclear war, and you're just launching one for some kind of military purpose, you'll probably want to launch from land to avoid giving away the position of one of your subs.
> Less time for the enemy to react, less chance of it being known who launched the missile, less chance of the enemy detecting the launch.
You'd really have to reach to come up with a scenario where the United States launched a ballistic missile and did not want anyone to know it had done so. In the absence of a nuclear war, you're going to be dealing with the opposite problem when launching an ICBM: making sure everyone knows what the US is doing so they don't freak out about it.
All the states capable of detecting a launch could pretty well figure out who had launched from a ballistic submarine, in any case.
In principle, accuracy: the depressed trajectories you're thinking of tend not to be the most accurate. If you happen to NOT be fighting a full-on nuclear war, and you're just launching one for some kind of military purpose, you'll probably want to launch from land to avoid giving away the position of one of your subs.
> Less time for the enemy to react, less chance of it being known who launched the missile, less chance of the enemy detecting the launch.
You'd really have to reach to come up with a scenario where the United States launched a ballistic missile and did not want anyone to know it had done so. In the absence of a nuclear war, you're going to be dealing with the opposite problem when launching an ICBM: making sure everyone knows what the US is doing so they don't freak out about it.
All the states capable of detecting a launch could pretty well figure out who had launched from a ballistic submarine, in any case.