Last weekend’s Israel-Hezbollah exchange of fire proves it: The terror group, and its Iranian paymasters, threaten big — yet when enemies fight back, they stand down.

So much for “escalation” — and a lesson for the Biden-Harris team.

On Sunday, the IDF preemptively took out 6,000 Hezbollah missiles aimed at the Jewish state.

The terrorists then got off just 300 (mostly intercepted or landed without causing casualties) — but then backed off, fearing a larger-scale war.

Even though they’ve been vowing major revenge for Israel’s assassination of top commander Fuad Shukr (the guy behind the slaughter of a dozen Druze kids last month and 241 US Marines back in 1983).

Iran, too, talked tough over Israel’s killing of Hamas boss Ismail Haniyeh in Tehran, but has yet to act.

Maybe because the one time it tried to attack, launching 320 missiles and drones in April, the result was . . . zilch.

And when the IDF responded to that by taking out Iran’s air-defense system near Iran’s Natanz nuclear facility, the regime did . . . nothing at all.

Hez and Iran say they still plan actions, but both clearly fear Israel’s might.

Hezbollah is believed to have 150,000 missiles, and chief Hassan Nasrallah claims 100,000 Hez fighters; the group could certainly inflict great damage in a full-scale war with Israel.

Yet it would take even greater damage in return.

Iran, too, has a considerable military.

But it’s no match for Israel — which would likely devastate its oil industry in response.

Uncle Sam is stronger than all of them, but the Biden-Harris braintrust keeps failing to respond seriously to threats and even attacks — for fear of “escalation.”

So Iran’s axis keeps pushing: The Tehran-backed Houthis just blew up a tanker, posting video of it to mock the West’s “protection” of sea lanes.

Iranian puppets killed three US soldiers in January — yet Biden-Harris barely wrist-slapped back.

The White House even told Israel not to respond to Iran’s missile barrage.

Insane.

When will Washington finally copy Israel’s approach, and call Iran’s bluff?

Not while Biden’s in the Oval Office, nor if Harris moves in.