I'm not going to get into a big debate about this, since it's not the thread for it and I don't have the patience. However....
As far as the Civil War, no, we should not have fought it, for a multitude of reasons:
- First of all, after making the slave trade illegal, we should have made serious efforts to buy up all of the existing slaves and free them before even considering a brutal and bloody war...which also happened to be much more costly than buying the slaves anyway.
- Second, once the southern states seceded, slaves could have simply escaped to the North and been safe, since the North would honestly no longer give a damn about enforcing the Fugitive Slave Act.
- Also, no matter how despicable the southern states were, states did in fact have a right to secede, and the federal government had no right to start a war against them just to bring them back.
- Besides, the Civil War wasn't even sparked entirely by the issue of slavery anyway. The North had also been trying to destroy the economy of the South for a long time, though I suppose you could always say it was just due to outrage over slavery.
- In any case, Lincoln himself didn't even care that much about slavery, and he personally admitted that he'd rather be able to bring the South back into the Union without abolishing slavery. All he really cared about was the tyrannical idea that states have no right to secede from the Union.
Bottom line: Every single other civilized country in the world ended slavery without war...we could have too, and so should we have.
In terms of World War II, it really depends on several factors, including the following two:
- How avoidable was Pearl Harbor? Did FDR know in advance? Did we purposely manipulate Japan into attacking? There are a lot of people who would answer, "Avoidable, yes, and yes," and while I'm not in the position to defend these claims, I certainly wouldn't discount them. If Pearl Harbor had never happened, we never would have needed to fight Japan.
- Did Germany's continued expansion pose a threat to the United States? (As a side note, World War II would probably NEVER have happened if we had not entered World War I and turned the tide of it...and that was a war which we had no good reason to join in the first place. Sure, we manipulated the Germans into giving us a pretext, but...)
In any case, why are those two questions even relevant to this thread?