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... Marine Expeditionary Units are trained and equipped to conduct amphibious landings, but they also specialize in bolstering security at embassies, evacuating civilians and disaster relief. While the deployment is a major increase of troops in the region, it does not necessarily indicate that a ground operation is imminent or will take place at all.

The 31st Marine Expeditionary Unit, as well the Tripoli and other amphibious assault ships carrying the Marines, are based in Japan and have been at sea in the Pacific Ocean for several days, according to images released by the military. Their location puts them more than a week away from the waters off Iran. ...