Henry Agard Wallace, the 33rd vice president of the United States, was a peculiar fellow.

He didn’t drink, smoke or swear.

He didn’t like telling jokes, reading fiction or playing golf. In fact, he hated any pursuit in which he could discern no scope for self-improvement.

While highly intelligent, Wallace struggled in social situations, as author Benn Steil explains in “The World That Wasn’t: Henry Wallace and the Fate of The American Century” (Avid Reader Press).

Steil believes Wallace actually had Asperger’s syndrome, a form of autism spectrum disorder first highlighted by Austrian physician Hans Asperger in 1944 — Wallace’s final year as vice president.

According to Steil, Wallace remains the most fascinating, “almost-president in American history” and in “The World That Wasn’t” he imagines how different America would have been if Wallace, and not Harry S. Truman, had succeeded Franklin D. Roosevelt in 1945.

Born on a farm near Orient, Iowa, in October 1888, Wallace was initially on an agricultural path.

After college, he edited the family newspaper, Wallace’s Farmer, and eventually bought his own farm where he developed hybrid corn and formed the successful Hi-Bred Corn Company.

Like farming, politics also ran in the family.

His father, Henry Cantwell Wallace, was US secretary of agriculture under presidents Warren G. Harding and Calvin Coolidge.

Wallace held the position himself under Roosevelt from 1933 to 1940, and then served as FDR’s vice president from 1941 to 1945.

While it seemed likely that FDR would ask Wallace to be on his ticket in his for bid a third term, his left-leaning views, especially regarding the Soviet Union, spooked some moderates in the Democratic Party.

Roosevelt instead chose Truman to be his running mate for the 1944 elections, so it was Truman who became president after FDR’s death in April1945.

While it seemed likely that FDR would ask Wallace to be on his ticket in his for bid a third term, his left-leaning views, especially regarding the Soviet Union, spooked some moderates in the Democratic Party.

That decision had long-term implications, not just for Democrats and America, but the world.

“This most unpromising of political figures [Wallace] came within a whisker of becoming FDR’s successor at a critical crossroads in twentieth-century geopolitics,” Steil writes.

“And even if the Cold War had only been delayed by a Wallace presidency, postwar history would no doubt have been very different because of it . . . With Henry Wallace in the White House, there would have been no Truman Doctrine. No Marshall Plan. No NATO. No West Germany. No policy of containment . . . All of these initiatives . . . Henry Wallace opposed.”

Wallace was the secretary of commerce under Truman but when he gave a speech urging more conciliatory policies toward the Soviet Union in September 1946, Truman fired him.

Wallace’s appeasement of the Soviets was clearly out of place in postwar America.

Nonetheless, Wallace doubled-down on his Soviet sympathies.

First, he wrote a book detailing his belief that the Soviet Union was experiencing a renaissance under the Bolshevik regime — and he did so with the help of a known KGB informant.