June 30

Operation Cartwheel Begins — Isolating Rabaul

MacArthur and Halsey launched a coordinated two-pronged advance through the Solomon Islands and New Guinea aimed at isolating and neutralizing the major Japanese base at Rabaul. The campaign would last 15 months.

Cartwheel's island-hopping strategy of bypassing heavily fortified Japanese positions while cutting their supply lines became the template for the entire Pacific campaign.