I realize that my main question might be a false assumption, and if so, telling me that would also answer my question. I just always grown up being told that December 7th was the reason why the US got involved. Despite that, the US forces in Europe drastically outnumbered the troops in the pacific. If I remember correctly, fewer troops were sent to the pacific than had died in europe.
That just seemed odd to me, given the "moral justification" for entering the war.
The decision to prioritize Germany First actually predated Pearl Harbor and was based on the practical imperative of winning the war rather than the moral justification of entering the war.
Anticipating that the U.S. would be drawn into the war, a strategy conference Called ABC-1 was held in Washington DC in January-March 1941, 12 months before Pearl Harbor. This conference was the place in which Anglo-American grand strategy was formulated. Subsequent events and discussions re-affirmed the overall grand strategy.
The main reason for this strategy was that Germany was far more dangerous as an opponent for Britain and America. Firstly, the German industrial base alone was far stronger than Japan's and when the Italian effort is added in, Europe's importance is stronger still. Secondly the Germans were geographically much closer to Allied and Neutral industrial regions than the Japanese were. In 1941, Germany controlled territory within (or almost within) logistical striking distance of the industrial heartlands of the Soviet Union and Britain. If Nazi Germany were to knock out either the U.K. or U.S.S.R., it would cause the war to become dramatically more difficult for the Allies. Barbarossa in late 1941 made this situation even more compelling. The sooner the Anglo-Americans could make a contribution in Europe, the less chance there was of a Soviet collapse or an Eastern Front stalemate.
In contrast, the largest Chinese industrial regions were already mostly controlled by Japan in 1941. Far Eastern colonies of the Allies were expendable in economic sense, because their resources were replaceable with substitutes like synthetic rubber, or other production sources. Due to logistical constraints, it was difficult for Japan to threaten the U.S. Mainland or Britain. Even secondary industrial centers like Australia and India were threatened only at the very end of long and tenuous supply lines, and serious invasion attempts proved impractical.
Overall, the decision to focus on Europe was safer and more likely to bring an end to the war quickly than focusing on the Pacific.
If I remember correctly, fewer troops were sent to the pacific than had died in Europe.
This isn't true. The U.S. sent approximately 1,250,000 troops to the Pacific for the invasion of the Philippines alone, while the KIAs for the U.S. were only 407,316 for the war
Source: Mark Harrison (ed.) The Economics of World War II: Six Great Powers in International Comparison