Her stay in Hawaii lasted until 23 October when she steamed out of Pearl Harbor in company with the battleship North Carolina, bound for duty in the western Pacific with the Fast Carrier Task Force.

Allen M. Sumner remained at Ulithi until 19 November at which time she departed the atoll to join Task Group (TG) 38.4 at sea.

That duty—punctuated intermittently by air alerts—lasted until the evening of 2 December when Allen M. Sumner set course for Ormoc Bay in company with the destroyers Moale and Cooper.

Reports from American aircraft earlier that day had indicated that an enemy reinforcement convoy was entering the bay that night, and the three warships were sent to destroy it.

Just after 2300 that night, the destroyers suffered the first of many air attacks when a Mitsubishi Ki-46 "Dinah" – a fast, twin-engine, reconnaissance plane – dropped a bomb which near-missed Allen M. Sumner about 30 yards (27 m) from the ship's starboard bow, pierced her hull with fragments, and started a fire on board.

Less than 10 minutes into the battle, Kuwa succumbed to the combined fire of the two destroyers, and the wrecked and burning mass began to sink.

Most of those were later rescued—but by PBY Catalinas rather than by Cooper's division mates who were still being subjected to heavy shore battery fire and air raids.

Though the area was subjected to intermittent air raids throughout that period, Allen M. Sumner recorded only one, long-range—in excess of 9,000 yards (8,200 m)—approach by an enemy aircraft on 6 December.

On 15 December, she moved in with the close covering group to participate in the preinvasion shore bombardment, and the subsequent landings went forward against negligible opposition.

On 2 January 1945, the destroyer stood out of San Pedro Bay, bound for the invasion of Luzon at Lingayen Gulf in the screen for the cruisers and battleships of Vice Admiral Jesse B. Oldendorf's Bombardment and Fire Support Group (TG 77.2).

The first plane retreated in the face of a heavy antiaircraft barrage while the second attacker hovered just out of range as a decoy to mask a run in by a third suicider.

She got underway again on 27 January in company with the escort carrier Kadashan Bay and, after stopping at Majuro en route, arrived in Pearl Harbor on 6 February.

Her renewal work was completed on 10 April and, four days later, she began duty training prospective destroyer crews along the west coast.

The ship reached Saipan three days later but soon resumed her voyage back to the United States arriving on the west coast in October and assuming duty as a training platform for prospective destroyer crews.

On 23 February 1947, Allen M. Sumner began an extended cruise to the Far East which included visits to Australia, the Marianas, the Philippines, China, and Japan before her return to the west coast for an overhaul and subsequent local operations.

Steaming by way of the Mediterranean Sea, the Suez Canal, and Indian Ocean, Allen M. Sumner arrived in Yokosuka, Japan, early in June.

After 10 days in port, she joined Task Force (TF) 77 in the Sea of Japan and began two months of duty as a plane guard and antisubmarine screening ship for the fast carriers while they sent their aircraft against targets in North Korea.

Over the next eight years, Allen M. Sumner alternated east coast and West Indies operations with seven deployments to European waters.

During that four-month assignment, the Suez crisis erupted, and Allen M. Sumner supported the evacuation of American citizens from Egypt at Alexandria.

She returned to the United States on 19 April 1961 and, on 17 May, began a fleet rehabilitation and modernization overhaul during which her antisubmarine warfare capabilities were improved and updated.

Allen M. Sumner completed her overhaul on 2 January 1962 and resumed her schedule of east coast operations alternated with Mediterranean cruises.

Soon after her return to American waters, President John F. Kennedy declared a "quarantine" of Cuba in response to the siting of offensive Soviet missiles on that island.

Upon her return to Vietnamese waters, Allen M. Sumner moved inshore with the Australian cruiser Hobart to resume "Sea-dragon" duty and, later, to provide shore bombardment support for marines engaged in Operation Beau Charger, a combined waterborne and airborne amphibious assault conducted near the demilitarized zone late in May.

Throughout 1968, she cruised the waters of the West Indies, frequently providing support for the encircled naval base at Guantánamo Bay, Cuba.

Following 10 months of normal operations put of Mayport, Allen M. Sumner embarked upon the final Mediterranean deployment of her career on 27 August 1970.