Here's what happens when US Marines storm an enemy beach

CAMP PENDLETON, Calif. - If thousands of Marines are off an enemy shore, it's typically an exercise in futility for bad guys to stick around and wait for the assault.

On Thursday, US Marines with the 15th Marine Expeditionary Unit embarked on a training exercise, carrying out an amphibious assault on a town littered with notional insurgents - and as should be expected from a premier maritime force, the grunts dominated.

Business Insider was on hand to watch as Marines left their ship, the USS America, and headed into shore, practicing landing on and taking over an enemy beach, something that they could potentially be tasked with once the MEU deploys later this year.

Here's what we saw.