Draka is an “easier to sell enemy” than Imperial Germany, and the US still fully committed to fight in WW1 when they entered the war, despite Wilson being elected with promises of peace.So, let me get this straight, your thinking the US will not only fully commit to supporting a war started by a self-serving traitor, but would actually exceed even his goals and commit to a major war in order to crush the Drakians even after removing said traitor. The reasons why this is impractical should be pretty self-evident
Also thinking the Drakians would fold after a major defeat is exactly the sort of thinking that got the US into this mess in the first place, the Drakians managed to survive the 1st World War and the occupation of much of West Africa, it survived the crucible, it would survive a major defeat in the field.
I don't see how tying down much of the American armed forces in Africa and fighting a major which would happen whatever the result of an American-Drakian conflict is going to improve American odds against the Indo-Japanese alliance. Furthermore, the US had basically already lost by the time the Second Drako-American kicked off, having been forced back to Australasia and the Eastern Pacific and having been kicked out of the IO entirely. the war was simply the final nail in the coffin for America's willingness to continue the fight.
So you'd rather see the US risk military tyranny just to one-up the snakes? Well I'm just gonna quote Franklin again
Drakian society is a society in the brink of collapse at all times, the crucible is the proof of that. They need an unimaginable level of brutality to keep the masses under control. If they are consistently defeated, then the whole country could fall apart. They wouldn't be capable of surviving to the full onslaught of the Grand Alliance alone AND keep the slaves under control.