Plumbers make sure that their piping repairs are leak-tight by testing them under pressure. Engineers pressure-test vital nuclear plant systems to ensure public safety. And in everyday life we learn a great deal about people (ourselves included) by their performance under pressure.

In April of 1961, President John F. Kennedy gave the green light to Operation Zapata, a CIA-sponsored amphibious assault by volunteer Cuban expatriates on a Cuban beach called the Bay of Pigs. Their objective, and that of the U.S. government, was to rally the Cuban public and overthrow the Fidel Castro regime.

The secretly planned insurrection (a real one) was grand in scope and more than a year in the making. The CIA acquired, outfitted, and disguised five ships and a small air force. They recruited, armed, and trained about 1400 insurgents, nearly all Castro-hating Cuban exiles.

The operation failed spectacularly. The poorly kept secret had been leaked and the Castro forces were ready. Within hours of the insurgents’ landing, they were pinned down by defending forces. Isolated, taking heavy casualties, and short of ammunition and medical supplies, they pleaded for U.S. Navy air support. Kennedy, fearing the risk of such a provocative action in the rapidly escalating cold war, refused.

Hundreds of the Cuban freedom fighters were killed on the beach or later executed. The remainder languished in Cuban prisons until repatriated — with ransom money provided by U.S. donors — in December 1962.

The entire episode was a humiliating defeat of “superpower” USA at the hands of an upstart communist island regime. It cemented Castro’s hold on Cuba and his alliance with the USSR.

Until that point, JFK — president for just three months — was a political rock star, larger than life, idolized by millions. In one grim morning, his stardom came crashing to earth, in full view of all, by his ill-advised approval of a foolish invasion.

Kennedy had every reason to feel snookered by his own government. The Bay of Pigs operation had been set in motion, long before he took office, by the previous administration — the one led by Dwight D. Eisenhower, the man who’d toppled the Nazi regime in WWII. Whatever misgivings Kennedy had about the idea were surely overshadowed by Eisenhower’s implicit endorsement.

Nevertheless, Kennedy immediately accepted full responsibility for the operation’s failure, noting ruefully that “victory has 100 fathers and defeat is an orphan.” How true.

The parallels and contrasts between Kennedy’s Bay of Pigs failure and Joe Biden’s Afghanistan fiasco are striking — and revealing.

Both were embarrassing U.S. failures, on the world stage, at the hands of lesser adversaries. Both were self-inflicted wounds. Both took a horrible human toll among those caught in the crossfire. Both led to serious American security consequences.

Kennedy and Biden were very different leaders — Kennedy young and brash, Biden old and seasoned — but neither was experienced in the incalculably difficult job of being president of the United States of America. Both had worthy goals: for Kennedy, ridding the hemisphere of communist influence, and for Biden, extracting U.S. forces from long, fruitless military engagement. And in both cases, the mission execution was abysmal.

But it’s the differences that matter. Joe Biden walked into the Afghanistan situation with eyes wide open, chose the manner and timing of American withdrawal, and announced it with pride. He was more than ready for the accolades; but when it all came crashing down, he ran for cover, blaming his predecessor, his allies, intelligence agency failures, and advice from his generals. Hundreds died in the artificially hurried, poorly planned evacuation, and many others have been left behind in a hostile land — all while our president arrogantly dodges accountability.

To be clear, John Kennedy was no saint. He was a politician, a good one. But whether by political calculation, moral compass, or just simple common sense, not once did he ever intimate that “Eisenhower made me do it.”

As awful as it was, the Bay of Pigs was a transforming event for Kennedy. It changed him overnight from pop idol to serious president. It changed his relationship with his military and civilian advisors and changed how he was viewed by our international allies and adversaries. It tempered him in office.

Most importantly, that searing experience prepared him to deal successfully with the Cuban missile crisis 18 months later — quite possibly the closest the world has ever come to nuclear war.

Performance under pressure told us everything we needed to know about John Kennedy in 1961 — and about Joe Biden last month.