On December 7, 1941, the sky over Pearl Harbor, on the Hawaiian island of Oahu, darkened with a wave of attacking Japanese aircraft. The attack on Pearl Harbor resulted in the loss of 2,341 members of the U.S. military and American entry into World War II.

Relations between the United States and Japan had been deteriorating long before the attack, says Daniel Martinez, chief historian at the World War II Valor in the Pacific National Monument in Honolulu, Hawaii. As tensions between the two nations escalated, the United States made Pearl Harbor the homeport of the Pacific Fleet, a group of U.S. Navy vessels in the Pacific Ocean. Hawaii was not a state at the time, and the fleet had only moved from California a year earlier.

“The Japanese strategy for the attack was pretty straightforward,” Martinez says. “It was to immobilize the Pacific Fleet and to take the Pacific Fleet out of action from at least six months to a year. The idea of a surprise attack was key to their success.”

Surprise Attack

American military personnel were involved in typical early-morning duties when the attack began, Martinez says. “[They] are getting ready for morning colors, church services, day-to-day duties, preparing to raise our flag,” the historian says. “On the battleship Nevada, they are playing ‘The Star-Spangled Banner’ as the torpedo planes are gliding in.”

Torpedo planes are bombers designed to attack ships, and they were only part of the massive air assault deployed by the Imperial Japanese Navy at Pearl Harbor. The assault, involving more than 350 planes, came in two major “waves.” In the first wave, torpedo planes targeted the docked Pacific Fleet. The air torpedoes used by these planes were equipped with rudders, which allowed them to operate in shallow water—such as a harbor.

The second wave was composed of dive-bombers and “Zeroes,” perhaps the best fighter aircraft used in WWII. Zeroes had an enormous range, able to fly more than 2,500 kilometers (1,560 miles) from their aircraft carrier. They were also agile, able to engage in steep climbs and drops.

The Japanese assault devastated the Pacific Fleet. Most of the fleet was aligned in “Battleship Row,” a series of docks holding the battleships West Virginia (with a crew of 2,300), California (2,200), Tennessee (2,200), Maryland (2,100), Oklahoma (1,300), Nevada (1,500), and Arizona (1,500), and the repair ship Vestal (466).

“The group of planes that flew over about 8:06 a.m. dropped the fatal bomb that went into the U.S.S. Arizona’s forward magazine and ignited over a million pounds of explosives,” Martinez says. “The ship literally erupted in a ball of flame and lifted out of the water, but effectively the Arizona’s life was extinguished. One thousand, one hundred seventy-seven officers, sailors and Marines were killed. It was the greatest loss of life of any warship in American naval history.”

Along with the U.S.S. Arizona, 11 other U.S. ships were sunk or beached during the Japanese offensive, including the U.S.S. Oklahoma, where 429 men were killed. The Arizona was a complete loss, and the carcass of the ship is an underwater memorial in Pearl Harbor. Other sunken ships, such as the U.S.S. California, were raised and repaired. In all, more than 20 ships were damaged in the attack.

Neighboring military facilities on Oahu were also hit by the Japanese air strike, including Marine Corps Air Station Ewa, Marine Corps Air Station Kaneohe Bay, and Wheeler Field and Hickam Field, operated by the Army Air Corps. These targets held planes and airstrips, so the attack delayed the ability of the United States to respond. The U.S. lost more than 160 planes, with almost as many damaged.

Eventually, American anti-aircraft guns and a few Army Air Corps pilots began to attack Japanese aircraft. By the time the Japanese left the area about 1 p.m., they had lost 29 planes.

The Japanese attack was not limited to aircraft. According to the U.S. Navy, the assault included aircraft carriers, cruisers, oilers, battleships, and destroyers.

The assault also included the use of submarines. The evening before the aerial assault, nearby Japanese submarines launched five midget submarines in the waters around Oahu. These midget subs were about 24 meters (80 feet) long, and held only one or two crewmembers. The personnel on these submarines were instructed to enter the harbor in the morning and do as much damage as possible.

One midget sub may have torpedoed the U.S.S. West Virginia, part of Battleship Row. The U.S.S. Ward, using depth charges and gunfire, sank a midget sub before the first wave of Japanese aircraft arrived.

Consequences of the Attack

Martinez notes that the Japanese attack on Pearl Harbor was carefully planned and, ultimately, very effective. “The Japanese in their attack had moved within 230 miles (370 kilometers) north of Oahu,” he says. “They had brought six [aircraft] carriers. This was unprecedented in history. This was the first time that a naval force would use that amount of planes, 350 aircraft. It was a total surgical strike to knock out our airfields, which they did within 15 minutes, and then knock out the Pacific Fleet, which they did within 20 minutes.”

But, while the attack was successful, it also had the effect of uniting the U.S. behind a war against Japan. “If you remove the emotion and look at it, the Japanese had achieved a great victory and success,” Martinez says. “But it was also the biggest public relations (PR) disaster any nation had done in the 20th century. In achieving that, they certainly outraged a nation and ensured their defeat.”

The day after the attack, in Washington, D.C., U.S. President Franklin Roosevelt addressed Congress and memorably referred to December 7, 1941, as “a date which will live in infamy.” Then he asked Congress to declare war against Japan. Three days later, Japan’s allies, Germany and Italy, declared war on the U.S., which signaled America’s entrance into World War II.

Commemorating the Attack

Martinez says that 70 years later, Pearl Harbor and its aftermath should be viewed as a turning point for the U.S. Although Hawaii did not become a state until 1959, the American military retained a strong presence on the islands. Pearl Harbor Naval Base is still the homeport and headquarters of the Navy’s enormous Pacific Fleet.

The consequences of Pearl Harbor resonate outside the United States as well. “It had such a resounding effect on reshaping the world and the United States,” he says. “The United States, who had been a minimal power prior to the war, became a superpower with the atomic bomb.”

The National Park Service, which manages the World War II Valor in the Pacific National Monument, will commemorate the 70th anniversary of the Japanese attack on Pearl Harbor by welcoming World War II veterans. The organization will also hold a symposium that looks back on December 7, 1941, and the Pacific theater of WWII.

“We will have our visitors pause, reflect, and honor the past at the ceremony,” Martinez says.

Martinez believes the events of December 7, 1941, are still relevant today. “I think Pearl Harbor has enshrined itself,” he says, “into one of those moments that is iconic to American history and world history.”