He had help from Herbert Hoover, who set records for government spending which FDR broke, blaming Hoover for the results.But yes, FDR had done plenty of damage before he “saved civilization” by getting us into WWII. His administration basically forced Japan to make the gamble which was Pearl Harbor. The only reason that gamble didn’t succeed is that the Navy’s carriers were not at home. Had they been destroyed - and they were the real targets - Japan would have not had their thust toward Australia blunted, American would have been worried about a Japanese invasion of Hawaii - and would have needed peace bad. Exactly what Japan planned.
Even as it was, Japan would have attained the same result at Midway with a little more luck; it was a close-run thing. And without Midway’s defeat, Japan couldn’t have been dislodged from Guadalcanal - and Australia could have fallen, leaving Japan in control of the whole western Pacific.
And having dodged those bullets, FDR saved the USSR from Hitler by an enormous supply effort - lots of trucks (delivered loaded with supplies), railroad locomotives by the shipload, not to mention the P-39s which didn’t suit American battle needs but which (aside from their requirement for high-octane gasoline which FDR also supplied) suited the Russians well given the altitude at which air battles were fought at “der Ostfront.” The Russians made a lot of their own fighter planes and their tanks &c, but that was easier to do when they had American food to keep some of them from starvation. And for all of that, what we got in return was the whole the Cold War.
When the Left is at the helm, our enemies are emboldened and wars start. Double-minded Leftist FDR was no exception.