Colonel Alva Lasswell, USMC, cryptographer who identified Midway Island as Japanese invasion target


Recently declassified documents about World War II cryptography reveal the vital contributions of Colonel Alva Lasswell, USMC, (father of our classmate Jim Lasswell) to the U.S. Navy’s victory at the Battle of Midway and other events in the war against Japan.   Tom Hunnicutt, the Historian of the Marine Corps Cryptologic Association (MCCA) has written a fascinating article about Colonel Lasswell.  That account appears below, through the courtesy of the author.



            Colonel Alva Bryan “Red” Lasswell is little known, but should be a person of special interest for the citizens of Northeast Arkansas.  Colonel Lasswell was born January 3, 1905 in Walpole, Illinois.  Later Alva’s family relocated to the small town of Piggott, Arkansas, where Alva spent the majority of his childhood and where he attended school though he never graduated.  The majority of Alva’s educational training came from his father home-schooling him.  Alva’s father, Charles Lasswell, was a school teacher, lawyer and farmer.  In 1921, Alva moved to Oklahoma where he worked as an accountant for a while.  As Alva Lasswell reached adulthood, he joined the U.S. Marine Corps where he played a vital role in changing the very course of history during World War II in the Pacific Theater.  Until recently Colonel Alva Lasswell and his affect on the outcome of World War II had been virtually unknown due to the high classification of his job duties while stationed on Pearl Harbor.  Without Colonel Lasswell’s contributions the War in the Pacific would have had a completely different history and possibly a different outcome altogether.


Roots of the War in the Pacific

In July of 1937 a conflict between Japan and the Republic of China became part of World War II.  In this conflict, Japan attacked China in an attempt to put a puppet government into position to control Japanese interests in that and surrounding countries.  Japanese activities in the south western Pacific caught the eye of a number of other nations concerning them with Japanese growing militarism.  In an effort to stem this Japanese militarism movement, the United States, Australia, Britain and the Dutch government in exile decided to stop the sale of natural resources that would supply Japan’s military activities.  Among these resources were iron ore, steel and oil, all of which Japan imported to make up a large percentage of their domestic needs.   This action taken by these Western powers came to be referred to by Japanese media as the “ABCD (American-British-Chinese-Dutch) encirclement.  These embargos were seen as acts of aggression by the Japanese government.  It was at this time that the Japanese government started planning for their coming war with the Western powers.

            To help counter the effects of the embargo by the Western powers, Japan planned to attack and take control of a number of British and Dutch controlled territories or island seizing and gaining control of the needed natural and economic resources.  The U.S. was viewed as an ally of Britain, so the Japanese believed there would be inevitable involvement by the United States.  Thus, Japan began their plans for the attack on Pearl Harbor, Hawaii.  Other aspects to the initial Japanese plans for war with the Western powers was an attack on the Philippines, cutting U.S. communications by attacking and seizing Guam and Wake, and isolating Australia and New Zealand.

            On December 8, 1941, east of the International Date Line, Japanese forces attacked the British Colony of Hong Kong, the U.S. controlled Commonwealth of the Philippines as well as launching an attack on Thailand.  December 7th is when Japanese forces, led by one of Japan’s leading military minds, Admiral Isoroko Yamamoto, executed the now infamous attack on U.S. Forces at Pearl Harbor using Carrier based aircraft.  The Japanese had hoped that the U.S., being hit with such a devastatingly massive and sudden defeat would negotiate with Japan and give them free reign to do what they wished in China.   Though the U.S. lost and received damaged to various battleships, the more important aircraft carriers were undamaged because they were out at sea and the naval infrastructure at Pearl Harbor that was a valuable U.S. asset in the Pacific was unscathed.


Early Military Intelligence

An extremely important aspect of the U.S. military infrastructure at Pearl Harbor that was often overlooked at the time was the special signals intelligence groups that operated out of what affectionately became known as “the dungeon.”  The signal intelligence group was initially known as “HYPO” but later came to be known as “FRUPac” (Fleet Radio Unit Pacific).  Thirty military personnel comprised the FRUPac group, ten of which were officers.  This little known group of American heroes was led by Commander Joseph J. Rochefort.  One of only two of the officers that were both cryptanalysts and Japanese linguists was also the only Marine in the group, Captain Alva Bryan Lasswell.

            In 1925, Alva joined the Marine Corps.  And by late 1928, he was recommended for Officer’s Candidate School and was commissioned to the rank of Lieutenant in January 1929.  Much like Japan’s Admiral Yamamoto being sent to the U.S. to study English and the American society and people, In 1935 Lieutenant Lasswell was sent to Japan to study Japanese where he stayed for three years.  In 1938, Lasswell was transferred to the Philippines where he worked with Naval Intelligence translating intercepted Japanese messages.   In 1941, Alva was transferred to Hawaii, where he eventually became the chief translator in the Communication Intelligence Unit in Fleet Radio Unit, Pacific or FRUPac.  Here is where Alva Lasswell would later play a personal role in changing the very outcome of World War II in the Pacific Theater.

            After the Japanese attack on Pearl Harbor, the Japanese went on a campaign of conquering as many of the islands of the south east Pacific as they could.  The Japanese had a certain amount of success while the American presence in the area was limited.  The Japanese had a fallback strategy in their conquest of the region in which they initially planned to seize as much territory as quickly as they could and then settle into a war of attrition to make the U.S. eventually come terms.  The pace of the Japanese conquest was rapid.  The Japanese started with their attack on Hong Kong on December 8, 1941 and from there they attacked U.S. bases on Guam and Wake, then moved on to invade Burma, the Dutch East Indies, New Guinea, the Solomon Island and capturing Manila, Kuala Lumpur, Rabaul, Bali and Timor.  By February 1942, Japan had advanced to a point where they were staging air attacks on the Australian city of Darwin.

            In January of 1942 is the first time for the use of the term “United Nations” with the signing of the Declaration by United Nations.  The united allied nations appointed the British General Sir Archibald Wavell as supreme commander to the American-British-Dutch-Australian Command.  By the end of February Wavell resigned this position and was replaced by the U. S. General Douglas MacArthur as Supreme Allied Commander South West Pacific and Admiral Chester Nimitz was given the responsibility for the rest of the Pacific.

            Japan continued its’ strategy of trying to take control of as many islands and territories as they could.  In time Japan’s grasp grew beyond their reach and the U.S. Navy and other military branches were able to greatly increase their presence in the area.   By mid-1942, the Japanese found themselves to be in control of a vast area without enough military resources to defend it and without logistical support for those that they did have.  At this point is when the American code breakers and the boys of FRUPac started to have an effect on the war.  It started intercepting and translating Japanese messages relaying strategic plans, the first of which was plans for an attack on Port Moresby, New Guinea which was turned back by the Allied forces.


Colonel Lasswell’s First Major Contribution

The first major contribution by Colonel Alva Lasswell to the eventual victory in the Pacific Theater came in mid-1942 when he translated an intercepted message that revealed Japan’s planned attack on Midway Island.  Upon Lasswell’s translation, the message was sent to NEGAT, which was the FRUPac equivalent in Washington, D.C.  NEGAT disagreed with Lasswell’s translation that Midway was the intended target and on which day the attack was planned.  Admiral Nimitz went to “the Dungeon” to speak with Captain Lasswell to ask how sure he was about his translation.  Lasswell advised he was 100% sure.  In order to verify Lasswell’s translation, Commander Rochefort devised a plan in which a fake message from Midway Command was transmitted stating there were problems with a desalination plant on Midway.  The Japanese intercepted the message and relayed this information verifying Lasswell’s accuracy.

Admiral Nimitz used Colonel Lasswell’s information to plan appropriately for what would become history’s first great carrier battle and what many experts view as the turning point of the war in the Pacific Theater.  After this great battle was won by the Allied forces, the Allies were finally able to go on a counter offensive that first began with the Navy, under Admiral Nimitz and Marine landings on Guadalcanal and the Solomon Islands.  Meanwhile, General MacArthur led the army and Australian allies in the taking of New Guinea’s Papuan Peninsula.  After this Admiral Nimitz and General MacArthur started on an island hopping campaign that skipped strongly Japanese held islands, isolating them and cutting them off from Japanese supply lines and reinforcements, in essence, taking the Japanese out of the war without having to actually engage them.


Lasswell’s Second Contribution

The next major war changing contribution of then Captain Lasswell, came on April 13, 1943, when he decoded and translated another Japanese naval message that was transmitting the intentions of Admiral Isoroku Yamamoto to fly to the Japanese held island of Rabaul.  The intercepted message even gave information about his escort fighters and the exact time of his arrival.  This information was relayed to Admiral Nimitz, who having been convinced of Captain Lasswell’s accuracy already, began planning the attack on Admiral Yamamoto’s aircraft, which was shot down on April 18, 1943.


Lasswell Saves General MacArthur

Once again Captain Lasswell proved his skills at decoding and translating Japanese messages when, on May of 1944, he once again worked his magic discovering a Japanese plot to ambush General MacArthur as he was returning from the European front.  The Japanese Navy was placing submarines every 7 miles in a stretch around the east coast of New Guinea on the route where they expected MacArthur would take in his return to the Philippines.  It is believed the Japanese were looking for a moral victory in retaliation for the killing of Admiral Yamamoto.  Because of Lasswell’s translation, this never played out.  Captain Lasswell had been told all 7 submarines had been destroyed, while a second independent source states that at least 5 of the 7 submarines were destroyed.


The end of World War II in the Pacific

            The major Allied objective in its conquests in the south east Pacific was to create airfields where the new large B-29 bombers would be in range for air strikes on Tokyo.  It was not long before hard fought battles on the Japanese Islands of Iwo Jima, Okinawa and others that resulted in terrible casualties for both sides and eventually led to the Japanese defeat.   The U.S. Strategic Air Forces proceeded with the strategic bombing that cut Japan’s industrial production nearly in half.  On August 6, 1945, the B-29 Enola Gay dropped an atomic bomb on the Japanese city of Hiroshima.  On August 9, another atomic bomb was dropped on Nagasaki.  These were the first Nuclear attacks in history and resulted in the deaths of 240,000 people. 

            Imperial Japan surrendered on August 15.  This day became known as “V-J Day,” which stands for “Victory in Japan”  The formal surrender  and treaty was signed on the battleship USS Missouri on September 2, 1945 in Tokyo Bay and was accepted by General Douglas MacArthur.


            Colonel Alva Lasswell’s contributions to the war in the Pacific Theatre went largely unknown until most recent years.  Only with the recent release of documents that were considered highly classified did the exploits and contributions of Alva Lasswell become uncovered.  Tom Hunnicutt, a retired Marine Corps. Officer and one time official historian of the Marine Corps Cryptology Association has requested and received copies of Colonel Alva Lasswell’s official United States military record as well as getting his personal notes and memoirs as written by Colonel Lasswell himself from his family.  Though Colonel Lasswell passed away from a personal battle with cancer in Vista, California on October 28, 1988, Mr. Hunnicutt has been working with the surviving Lasswell family in an effort to get Alva recognized with a much deserved Congressional Medal of Honor and to have him put into his proper place in the National Security Agency’s Hall of Honor.   Though few people know who Colonel Alva “Red” Lasswell was, he is a Northeast Arkansan everyone should know about and of whom everyone should be proud.