Whenever a conflict erupts somewhere in the world, invariably there are calls for the United States to intervene. If there are no actual United States interests at stake in the conflict invariably the argument comes up that if Hitler had been opposed early enough there would have been no World War Two.
There is only one valid response to arguments from Hitler, and that is to point out that the person making the argument that World War One proves intervention necessary.
It is inarguable that way World War One ended was the primary cause of World War Two. The only way to avoid that point is to only look at causes that occurred after Hitler’s rise to power in Germany.
Starting the search at that point and forbidding earlier causes is intellectually not a supportable practice. The only reason to do so is to advance a particular political agenda, but those who support that agenda do so fiercely and insist on only analyzing causes that support interventionism and never analyzing causes that oppose it.
The largest contributing factor to World War Two was the resolution of World War One. The Treaty of Versailles imposed overly harsh and punitive terms on Germany. The economic damage caused by the harsh terms, coupled with the social insult of being made to admit full fault in a war that was as much the fault of France as it was Germany and having those terms imposed even though foreign troops never actually entered Germany laid all the groundwork for the rise of Hitler and the waging of World War Two.
If it were not for the Treaty of Versailles, there would have been no World War Two.
The Treaty of Versailles was made possible by the intervention of the United States, both before and after the United States entered the war officially. Before the United States declared war the support given to the Allied Powers gave them an edge against the Central Powers in terms of supplies. It was an open secret that the United States was shipping munitions to Great Britain, and that the submarine warfare that Germany condemned so loudly was aimed at munitions. Sinking a cargo ship full or arms was not sufficient to for President Wilson to goad the USA into war, which is why they were later shipped on civilian cruise ships.
Even with that edge, the Central Powers were able to maintain the stalemate that was draining the wealth and population of both sides. That is why President Wilson was seeking a plausible excuse, such as the Lusitania, to actively involve United States troops. The entry of a powerful country that was not drained by several years of warfare was too much for the Central Powers to withstand, and the war ended with an Allied victory that made the Treaty of Versailles possible.
If it were not for United States entry into World War One, there would have been no Treaty of Versailles.
Anyone who expresses the idea that World War Two proves interventionism is sometimes necessary is, if educated, expressing the idea that Wilson’s intervention against Germany is an example of necessary interventionism. The two wars are the same war.
The causes of World War One itself are also examples of interventionism on the part of the European powers. Germany and Italy, late in becoming unified countries compared to the Renaissance unifications of France, England, or Spain, were behind on the drive to have colonies in distant lands. France and England ruled large parts of Africa and Asia, while Spain had ruled large parts of the America. Both Germany and Italy were able to grab parts of Africa. Austria-Hungary was left out of the colony race completely so tried to compensate by picking up the pieces of the decaying Ottoman Empire. Before the fighting actually started the Allied Powers were those with colonies (and also Russia which while lacking colonies had large amount of land within Russian borders ready to colonize) while the Central Powers were those without many colonies, including Italy even though it was an Allied Power once the shooting started, and also including the Ottoman Empire which while large was decaying at a rapid pace, in effect losing colonies.
Since none of the European powers were able to mind their own business the series of alliances formed that led to a small conflict exploding into a world war.
World War One was the disastrous result of intervention gone haywire, leading to further intervention, leading to devastating results that are used to justify intervention.
No sensible, educated, and honest person can use World War Two as a justification for intervention given that it is the result of layers of intervention piled up until the result was Hitler. A better argument for intervention needs to be found for those who advocate meddling in the conflicts of others.