The Allies captured key islands to use as bases and skipped others, leaving Japanese garrisons cut off.
Japan's empire was spread across many islands and long sea routes. At the Battle of Midway in June 1942, Japan lost important aircraft carriers. After that, growing Allied air and naval power let the Allies choose where to attack.
Island hopping meant capturing useful islands and skipping others. A captured island gave airfields and ports. From there, planes and ships could reach the next target. In 1944, bases in the Marianas let long-range bombers attack Japan regularly.
A garrison is a group of troops defending a place. A Japanese garrison left on a skipped island still held it. But cut off from supplies, it could not stop the advance. Skipping it saved lives and time. Still, some of the islands the Allies did attack cost many lives.
- Midway, June 1942
- Japan loses key aircraft carriers.
- Island hopping
- Capture key bases; skip and isolate others.
- Marianas, 1944
- Bases that let bombers reach Japan.
Worked example: Does holding an island stop the advance?
A cut-off Japanese garrison stays on its island while Allied forces move past.
- Ask whether the troops can get supplies or block the Allied route.
- If not, they hold the island but cannot affect the war.
- So the Allies can use their forces elsewhere.
Watch out for this
Island hopping meant attacking every island in turn.
It meant attacking only useful islands and skipping the rest.
Check your understanding
Why did the Allies skip some Japanese-held islands?
- Those islands had no Japanese troops.
- Cut-off garrisons could not stop the advance, so attacking them was not worth the cost.
- The Allies had no ships to reach them.