Why did japan wanted to seize the pacific islands? they wanted a strategic attack position. they wanted a place to which they could retreat. they wanted the natural resources of the land. they were trying to create a new territory.

The answer is: they wanted the natural resources of the land
Even though Japan has enough resources to fulfill their agricultural needs, the region is not blessed with other important natural resources such as metal.
Since metal is necessary material in the creation of weapons and automobiles, Japan decided to seize Pacific island to fulfill their needs of metal.