Operation Flintlock takes Kwajalein and applies Tarawa's lessons
A 15,000-ton bombardment secures the Marshall Islands in a week
Quick facts
- Location
- Kwajalein Atoll, Marshall Islands
- Dates
- January 31 to February 7, 1944
- Overall commander
- Vice Admiral Raymond Spruance
- Bombardment
- About 15,000 tons of ordnance
- Result
- US capture of Kwajalein and Roi-Namur
What happened
On January 31, 1944, US forces launched Operation Flintlock against Kwajalein Atoll in the Marshall Islands, the first major American amphibious operation to apply lessons learned two months earlier at Tarawa. Under the command of Vice Admiral Raymond Spruance, the Army's 7th Infantry Division landed on Kwajalein Island while the 4th Marine Division assaulted Roi-Namur, following a bombardment of roughly 15,000 tons of naval and air ordnance, one of the heaviest concentrations of firepower used in the Pacific to that point, so thorough that Army engineers found little demolition work left to do when they came ashore. Both atolls were declared secure by February 7.
Why it matters
Flintlock validated the doctrinal changes made after Tarawa's high casualties: better tidal planning, longer and heavier bombardment, and closer coordination between naval gunfire and landing waves, at a fraction of Tarawa's casualty rate. The Marshall Islands campaign also gave the United States forward air and naval bases that shortened the remaining distance to the Marianas and, eventually, Japan itself.
How we know
Naval History and Heritage Command's official history and its H-gram series both document the bombardment tonnage and the command structure under Spruance, Turner, and Holland Smith.
Sources
- Naval History and Heritage Command. Invasion of the Kwajalein Atolls, January 31-February 7, 1944 · Reputable sourcehistory.navy.mil · The domain "history.navy.mil" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
- Naval History and Heritage Command. H-026-1: Kwajalein 1944 · Reputable sourcehistory.navy.mil · The domain "history.navy.mil" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
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