Marine defense battalions

Unlike the mobile Marine forces involved in offensive actions, defense battalions were detached to key outposts, in the Pacific and one in Iceland,[1] and remained at the station they defended.

They conducted "fixed" defense exercises on Culebra Island of Puerto Rico throughout the first half of the 20th century, and other areas around the Caribbean.

The first battalions were created in 1939, when the outbreak of World War II caused concerns that overseas bases might be attacked by the Imperial Japanese Navy.

[4] Defense battalions deployed early and often throughout the Pacific campaigns, serving in a succession of distant places, some dangerous, others boring.

The Marines of the defense battalions endured isolation, sickness, monotonous food, and primitive living conditions for long periods, as they engaged in the onerous task of protecting advance bases in areas that by no stretch of the imagination resembled tropical paradises.

On 4 June, the Marines at Midway Island fended off a Japanese aerial attack, which contributed to the victory of the naval battle hundreds of miles away.

Only the 6th, the 51st, and the 52nd remained designated as defense battalions; the rest had become anti-aircraft units under Fleet Marine Force, Pacific.