The US strategy in the Pacific was to establish conquered areas as democratic republics.
attack Japan from newly gained territory.
use the islands as nuclear test sites.
O uncover Japanese intelligence information.

Attack Japan from newly gained territory.

Explanation:

During world war II, United States implemented a strategy called Island Hopping during our Fight Against Japan.

Rather than focusing our forces to attack the main land, US mobilize its military to conquer the smaller island first. Those smaller islands tend to have lesser defense and much easier to defeat.

Overtime, Japan will gradually lost part of its territory until eventually USA managed to established their army in newly gained territory and surrounded Japan from all sides.

alaska is the answer to this