LogFAQs > #963067822

if it's an icbm from the maximum distance of western russia to eastern US via the pacific ocean then it'd take about

"Long-range: more than 5,500 kilometers (approximately 3,410 miles), also known as intercontinental or
strategic ballistic missiles. Intercontinental ballistic missiles (ICBMs) can fly much further than the
minimum range; for example, Russia could hit Chicago with an ICBM launched from the Krasnoyarsk
ICBM base, which is located 9,156 kilometers (5,689miles) away." (Center For Arms Control and Non-Proliferation)

This missile would take an average of 25 minutes depending on how well the launch goes, but would be detected pretty much as soon as the silo doors even wiggle

...

On the other hand a submarine launched missile would have almost no warning and could hit within 30 seconds.