In 1943, the 1st Cavalry Division turned in its horses and tanks and became an infantry formation, slated for service in the Pacific. By 1944, they were in New Guinea preparing to capture the Admiralty Islands from the Japanese. The islands had a large harbor and space enough for large airfields. Their capture would complete Operation Cartwheel and sever Rabaul. (Not that it really mattered: the Japanese had already written it off. The Allies didn’t know that though.) More critically though, the Admiralty Islands were a perfect staging area for operations against the Palau Islands and, most importantly for MacArthur, the Philippines.
On 23 February 1944, three American bombers overflew the Admiralty Islands, and were not fired upon. In their arrogance, the Fifth Air Force automatically assumed the islands had been evacuated (The Japanese were conserving their ammunition). The Fifth Air Force commander went straight into MacArthur’s office and suggested an immediate landing. MacArthur’s G2 (intelligence officer) vehemently disagreed but MacArthur, ever the glory seeker, authorized an immediate “recon in force” with one of the 1st Cavalry’s squadrons.
There were over 4000 Japanese waiting on the islands.
On 28 February 1944, 500 troopers of the 2nd Squadron of the 5th US Cavalry, loaded on a few fast transports and destroyers, and headed north. They landed on a secluded beach along the southern shore of the island of Los Negros. The Japanese were taken completely by surprise, because they were all defending the large harbor at Seedler Bay which is where they expected the Americans to assault. The beaches in the south were too small to support a landing capable of seizing the rest of the islands.
The Japanese were convinced this was a diversion. 2/5 Cavalry had secured the beachhead but could advance no further without endangering it (a mini Anzio). But with no further American landings, the Japanese decided to destroy the beachhead on the night of 2 March. Just after sundown and all throughout the 3rd, 2000 Japanese attacked the small exposed beachhead perimeter. Only massive naval gunfire and air support allowed the troopers to hold the line. The 2nd Squadron 7th Cavalry was landed that afternoon to reinforce the small beachhead.. As the Japanese were rolling up both ends of the beach, 2/7 Cavalry landed into the Japanese defenders. They thought they were just offloading into a secure beachhead, but instead most of the squadron assaulted onto an opposed beach. But in true cavalry fashion, they arrived just in the nick of time to prevent the beachhead’s destruction
Once the rest of the division back on New Guinea heard of 2/5 and 2/7 Cav’s predicament, they commenced a hasty and confused embarkation to relieve their besieged brethren. The rest of the 1st Cavalry Division arrived in the Admiralty’s over the next few days. Los Negos was secure by the end of the month, but the 1st Cavalry Division fought on until May against dug in Japanese defenders to secure the rest of the Admiralty Islands for MacArthur.