The Pacific war started on December 7th 1941 when Japan launched an unprovoked attack on the United States naval base of Pearl Harbour seeking to destroy the American Pacific fleet based there.
The attack on Pearl Harbour was deemed a success by the Japanese in that it destroyed substantial elements of the American Pacific Fleet.
It was, however, a massive failure in that it failed to eliminate the American aircraft carriers, that were at sea, or critical infrastructure such as fuel depots and service installations. More importantly it galvanised the American people into unilateral action against the Axis powers.
Air power was a critical factor in the Pacific campaigns. Aircraft carriers were a key element in providing the American fleet with the potential to attack targets over the horizon.
There were a number of carrier actions during the war, the most notable being the Battle of Midway, during June 1942, when aircraft from the American carriers: Yorktown, Hornet and Enterprise sank four Japanese carriers for the loss of Yorktown.
Japan had established a defensive ring of island fortifications around the Pacific. American strategy was to assault some of these and isolate the others, starving the garrisons into submission.
The Pacific is huge, with few prepared airfields.
Flying boats provided to means to project power to many isolated corners of the war zones that would have been inaccessible to conventional aircraft.
Fighting in the jungle was very challenging,: there were few roads that could take the weight of heavy equipment; visibility was limited and combat was often at close range and personal.; the terrain made it extremely difficult impossible to deploy armour.
Occasionally the Japanese would mount a last ditch "Banzai" charge, in which a large number of infantry would charge "en masse' in the hope of breaking allied morale and forcing a retreat.
The M1917A1 was a belt-fed watercooled light machine gun used by the American army and Marines. It could fire up to 600 rounds per minute and was very useful in the jungle.
Island assaults required amphibious vehicles that sometimes needed to cross coral reefs on their way to the beaches.
The US Marines had a range of specialised amphibious Alligator LVT's (Landing Vehicle Tracked) available, which were developed from a hurricane rescue craft designed by John A. Roebling before the war. LVT's were first used at Guadalcanal in 1942.
The LVT(a)-4 was a version that carried a small howitzer to provide close infantry support during and after the landings. Being tracked meant that LVT's were particularly useful in the Pacific; they were well equipped for crossing coral reefs on their way to the beaches. Other craft had to avoid such obstacles or risk becoming beached.
In the Pacific the American Navy managed to do what the German Kriegsmarine had failed to do in the Atlantic.
The systematic attack of shipping in and around Japanese home waters denied them access to vital war resources, particularly oil, from their overseas empire.