How did Congress revive the draft law after Japan's attack on Pearl Harbor?
I would argue that it is wrong to say that Congress “revived” the draft law after the Japanese attack on Pearl Harbor on December 7, 1941. In order for something to be revived, it has to be dead or at least in some sort of major difficulties. This was not true of the draft law. There was a draft in place even before Pearl Harbor and Congress just altered the terms of the law after the attack.
In September of 1940, the US Congress passed the nation’s first law instituting a draft in peacetime. This was the Selective Training and Service Act of 1940. It said that all men between the ages of 21 and 45 to register for the draft. In October of that year, men started to be drafted for a one-year term of service. This meant that there was already a draft system in place even before Pearl Harbor was attacked.
After Pearl Harbor was attacked, the draft obviously had to be widened. Congress amended the draft law to broaden the age range of men to be drafted. They now required all men from ages 18 to 65 to register and said that men aged 20 to 45 could actually be drafted. They also changed the term of service from one year to the duration of the war plus six months.
Thus, Congress did not really have to revive the draft. Instead, it simply broadened a draft that was already in place.