I'm sure they can get called to fight.
Iraqhttp://usmilitary.about.com/od/coastguard/a/uscgwar.htmThe U.S. Coast Guard is an active player in the war on terror, both in Southwest Asia and on the home front, according to Adm. Thomas H. Collins, commandant of the Coast Guard.
Collins said the "fifth armed service," and the only one to fall under the Department of Homeland Security, is making its largest commitment to port- security operations since World War II. At the same time, the Coast Guard has deployed its largest contingent of Coast Guard members and assets overseas since the Vietnam conflict, in support of Operation Iraqi Freedom.
At the height of the conflict, Collins said the Coast Guard deployed 1,200 men and women, 11 ships and a port-security unit to the theater to conduct maritime-interception operations and coastal-security patrols. The port- security unit and five — soon to be six — patrol boats remain on duty in the northern Arabian Gulf, where they work closely with the Navy and Marine Corps under the command of U.S Naval Forces Central Command
Vietnamhttp://www.uscg.mil/hq/g-cp/history/h_tulichvietnam.html WWII http://www.amazon.com/exec/obidos/tg/detail/-/0071424016/002-1684204-9952801?v=glance"An exquisitely researched, thoroughly absorbing history of the Coast Guard's role in the greatest sea battle ever fought."—Stephen Coonts, bestselling author of the Jake Grafton series
"Bloodstained Sea is one of the most riveting accounts of naval combat history I've seen, and a valuable reference for any military and naval enthusiast."—Vince Patton, Master Chief Petty Officer, U.S. Coast Guard (Ret.)
In November 1941, America was not yet officially at war. Nevertheless, under orders from President Roosevelt, sailors of the U.S. Coast Guard painted their gleaming white cutters battleship gray and steamed into action against the menacing U-boats of the Third Reich. Bloodstained Sea recounts how, over the next four years, these men—normally dedicated to saving lives and rescuing ships in distress—would be locked in one of the longest and bloodiest running sea battles in history.
Americans called it Torpedo Junction; to the Germans, it was Devil's Gorge. By any name, the North Atlantic of the early 1940s was one of the most dangerous fronts in a catastrophic war. Called upon in desperate times, seven of the Coast Guard's finest ships—the sleek, efficient, tough 327-foot Secretary Class cutters—plied these unforgiving waters to protect convoys of troops and much-needed supplies.