President Franklin Delano Roosevelt saw the writing on the wall…and it said something like, "Hitler's a monster and must be stopped, and it's going to take the United States to stop him."

Which: yes. That's correct.

Unfortunately, for much of the 1930s, most people in the United States—and even many in Europe—thought it would be better not to get involved in European conflicts again after the mayhem that was WWI. This ostrich-with-head-in-sand mentality is known as "isolationism."

Fearing WWII would cross the pond to American soil, FDR spent his first two terms chipping away at the support for isolationism, both in Congress and in the public-at-large. However, the U.S. government and its people were stubborn—it wasn't until the fall of France and the Battle of Britain (a.k.a. "the Blitz"), that a change took place in the form of the Lend-Lease Act.

You know: the doc that you're reading about right now.

This act allowed FDR to direct military aid to nations fighting against the Axis Powers…without the isolationist restrictions of the Neutrality Acts of the '30s.

Some might think that the U.S. didn't care about what was happening in Europe in the late 1930s and early 1940s, but that wasn't quite the case. The United States had actually been selling military equipment to, and otherwise supporting, the United Kingdom's war efforts under the terms of the Neutrality Acts, specifically an agreement known as "cash and carry," which sounds like the name of a convenience store, but was more about war materials and less about Big Gulps and Family Size packs of Twizzlers. It necessitated cash up-front and required the customer country to transport the goods themselves.

The beauty of the Lend-Lease Act was that it allowed the President to "lend" or otherwise give away military equipment and information, as well as supplies in any way related to the war, to any country they thought needed them. (This is pretty different from, say, the kind of lending that goes on at a bank.)

The United Kingdom, in particular, benefitted from these terms, as their cash reserves (based in gold) were heavily depleted from spending it on war supplies. Lend-Lease would eventually significantly support another wartime ally, the Soviet Union. By the end of the war, the U.S.S.R. would receive huge amounts of material support as it strained to repel the enormous Nazi invasion of their Eastern borders.

Under the terms of the Lend-Lease Act, the supplies of war goods were to be repaid, in part, by the leasing of military bases around the world to the United States, a component to the law that mostly just formalized the United States logistical entry into the war and set the stage for future troop and intelligence movements.

In other words, the Lend-Lease act was a) what helped halt Hitler's dreams of world domination and b) secured the U.S.'s future as a superpower. Both of these are pre-tty important when it comes to shaping the 20th century.

The United States remained officially neutral until the attack on Pearl Harbor on December 7th, 1941, nine months later. But in reality, all pretense to neutrality ended when "cash and carry" upgraded to "locked and loaded" with the successful passage of the Lend-Lease Act.

Some wise guy once said, "neither a borrower nor a lender be." Sage advice, for sure, if you're living in the luxury of peacetime.

But "all's fair in love and war," which pretty much means that that sage-but-dusty advice takes a trip to the circular file. With WWII on like Donkey Kong, nations like the U.S.A. and the U.K. (along with their allies) basically had no choicebut to become both borrowers and lenders. The other option was just straight up taking...but that's what the Germans were doing, and nobody was happy about it (except the Germans).

The Lend-Lease Act is a sneaky thing. On the face of it, it doesn't sound like a military declaration of war. Which is because technically it wasn't—it sort of sidestepped the issue because isolationism was still fairly popular in the U.S. come 1941.

However, FDR and his administration knew that Great Britain couldn't sustain a long-term war with Germany without, at the very least, significant material support from the United States. As for FDR and his administration, they surely knew about the inevitability of the American military getting drawn into the fray.

Lend-Lease was the next step in a soft preparation for possible entry into war (it wasn't exactly a "take the plunge" kind of scenario). Prior to the passing of the act, FDR had negotiated changes to the Neutrality Acts in the late 1930s that allowed for the "cash and carry" sale of hardware to allies who could pay cash up-front and provide for the transport themselves.

It's like buying a used refrigerator online—it's kind of a good deal, but also kind of inconvenient.

The Lend-Lease Act replenished British airplane hangars and supplied them with everything the American industrial base could produce as fast as they could make them. When the Soviet Union was invaded by Germany, the United States brought them into the fold and began shipping life-saving supplies and weapons. Hundreds of thousands of American trucks were critical to keeping the Soviet defensive lines supplied, as well as enabling faster Soviet advances once the tide turned against the Nazis after 1942.

So yeah: who knows what would have happened in terms of WWII—and, you know, modern world history—if the Lend-Lease Act hadn't been around.

The Lend-Lease Act created the possibility for an Allied victory against the Axis powers, and it effectively (and literally) gave nations like the U.K. and the U.S.S.R. a power boost at a point in time when Germany was gaining ever more control over Europe.

Without this American aid, it's likely that Great Britain would have fallen, and a Fascist domination of the continent made possible. It's chilling to think about the possibility of a Nazi victory, and even more incredible to consider that something as straightforward as a simple text could lead its prevention.