THE UNREVEALED WAR ALERT OF
THE PANAMA MOBILE FORCE
10 DAYS BEFORE PEARL HARBOR

About a month before Japan attacked Pearl Harbor I began to believe that Major General Walter E. Prosser, Commanding General of the Panama Mobile Force, was expecting the Japanese soon to attack American forces, perhaps even in Panama. He ordered more realistic maneuvers, including one in which I led 12 “saboteurs” landing at night and making our way through jungle for two days, each of us carrying “explosives” (a 25-lb. box of rocks), a rifle, personal gear, and rations and other gear, until we reached and “de-stroyed” our objective. And at my urging he authorized his command’s first Jungle Platoon to keep in its barrack the rations and everything else needed — except ammunition — for a 2-week unsupported combat mission in a remote jungle area. Having ammunition in barracks was prohibited by long-established Army policy, because if soldiers have ready access to ammunition they are more likely to shoot each other. This prohibition made little sense to soldiers stationed at Fort Clayton during an escalating crisis, because the ammunition for all Army troops on the Pacific side of the Canal Zone was stored miles away from Fort Clayton.

That restriction on the first Jungle Platoon’s capability to move out and fight within minutes of receiving an order was permanently removed 10 days before Pearl Harbor when Major General Prosser ordered his whole Panama Mobile Force to go quietly on a war alert. On that date, November 27, 1941, Lieutenant General Frank Andrews, the Commanding General of the Caribbean Defense Command, was in Washington and Major General Prosser had taken over his duties in the Caribbean while he was away. That is how Prosser, my general, happened to receive (as I learned years later) a slightly modified version of War Department Message No. 472, signed “Marshall”:

Negotiations with Japan appear to be terminated to all practical purposes with only the barest possibilities that the Japanese Government might come back and offer to continue. Japanese future action unpredictable but hostile action possible at any moment. If hostilities cannot, repeat cannot be avoided the United States desires that Japan commit the first overt act. This policy should not, repeat not, be construed as restricting you to a course of action that might jeopardize your defense. Prior to hostile Japanese action you are directed to undertake such reconnaissance and other measures as you deem necessary but these measures should be carried out so as not, repeat not, to alarm civil population or disclose intent. Report measures taken. Should hostilities occur you will carry out the tasks assigned in Rainbow Five [the Army’s basic war plan] so far as they pertain to Japan. Limit dissemination of this highly secret information to minimum essential officers.

Ten days before the Japanese struck Pearl Harbor this famous war warning was received by Lieutenant General Walter C. Short, Commander of the Hawaiian Department. With minor alterations in phraseology, this highly secret message also was sent to Admiral Husband E. Kimmel, Commander in Chief, U.S. Pacific Fleet, to General Douglas MacArthur in the Philippines, to the Western Defense Command at the Presidio in San Francisco, and to the Caribbean Defense Command. (See At Dawn We Slept, the informative, 873-page account of Pearl Harbor written by Gordon W. Prange and published by McGraw-Hill Book Company.)

Of all the commanders who received this warning, Major General Prosser was the only one who interpreted it correctly. He cautiously put his own command, the Panama Mobile Force, on alert, but did not alert any of the other components of the Caribbean Defense Command. Not until five years later did General Prosser tell me that he had feared that by putting the Panama Mobile Force on alert he was going against President Roosevelt’s game plan.

While a storm of giant snafus was battering Pearl Harbor and the Philippines, the unreported ones that occurred in Panama did not result in disasters. However, the snafus that afflicted the Panama Canal Zone were so typical of correctable chronic weaknesses in America’s defense forces that they should be revealed.

With December 7, 1941 still 10 days ahead, General Prosser summoned me into his office at Fort Clayton and told me that there was increased danger of the Japanese attacking, and that he was putting the Panama Mobile Force on alert. I was greatly surprised when he ordered me to transmit to Brigadier General Robert H. Lewis, who commanded all Panama Mobile Force units on the Atlantic side of the Isthmus, the short oral order that Prosser slowly gave me. He ordered me to repeat it twice to him and not to mention it to anyone except General Lewis. Finally, he told me to take the train, which was about to leave, to the Atlantic side. At that time there was no road across the Isthmus. His car, with flags furled, sped me to the railroad station.

While on the little train slowly winding around and over jungle-clad hills, I kept repeating to myself that short oral order, wondering how near we were to war. I do not remember the exact words of the order, but do recall that it did not specify what type of attack to expect, or what measures General Lewis should take. I assumed there were secret standing alert orders concerning which I knew nothing.

Brigadier General Lewis met me at the station, a bit mystified at having received a phoned order to do so. While his car, flags unfurled and flapping noisily, was taking us to his headquarters, I gave him General Prosser’s brief oral order. Of course General Lewis wanted background information and an explanation as to why the order was verbal. I could answer none of his questions, and promptly departed to catch the next train back to the Pacific side.

Putting the Panama Mobile Force on alert status did not include preparations to promptly engage and eliminate sizeable attacking forces, as I had assumed would be done. However, ammunition was issued to most Mobile Force units, including the first Jungle Platoon. “My” platoon was permitted to keep several boxes of cartridges and two boxes of hand grenades in its barrack in Fort Clayton, with at least one soldier guarding them 24 hours a day.

General Frank Andrews returned from Washington a few days after Major General Prosser had alerted the Panama Mobile Force. As I learned from General Prosser after he had retired, General Andrews was surprised to find one of his Caribbean Defense Command units on alert, and all the rest — along with the Panama Canal Zone — in their usual unready peacetime state.

Within hours of Andrews’ return, Prosser called off his prudent but very unpopular alert, giving no explanations. Bright lights and the easygoing, boring peacetime life of U.S. Army posts, complete with an endless round of parties for officers and their wives, again became the norm in the Panama Mobile Force. Most ammunition went back into storage far away from the troops. However, General Prosser permitted “my” first Jungle Platoon to continue keeping in its barrack a two week supply of ammunition for its Model 1903 rifles and Colt .45 pistols, and two boxes of grenades.

Everything that the Jungle Platoon would require for an unsupported two week mission was kept in its barrack. Each man’s rucksack contained all he would need, except for ammunition and ready-to-eat dry rations. Those were in boxes in the barracks, the food in sealed cans. His rucksack was a copy, made to order in the Canal Zone, of the Norwegian framed rucksack which I had bought in England and had found best for use in jungles and mountains. It was much like the lightweight framed rucksack that our infantrymen a generation later appreciated in the Vietnam War.

A very few days before the fateful “day that will live in infamy,” I ordered a 3:00 a.m. surprise practice alert of “my” Jungle Platoon, the first specially equipped for jungle operations. That test alert proved that the platoon could be awakened unexpectedly and move out in trucks within 30 minutes, carrying everything needed for an unsupported two week mission against an enemy. Because of preparations made during the recently aborted war alert of the whole Panama Mobile Force, that one platoon probably was the only infantry outfit in the U.S. Army well prepared for immediate combat on the day the Japanese attacked Pearl Harbor.