It's time for the United States to hold Iran accountable.

Now that we know President Obama paid Iran $1.7 billion — $400 million in cold hard cash loaded on a secret flight — to ransom four American captives, comes an obvious question: What did Tehran do with all that money?

To hear Team Obama tell it, Iran’s windfall went for strictly benign purposes.

Just last week, CIA Director John Brennan claimed the money Iran is getting under Obama’s nuclear deal “is being used to support its currency” and “build up its infrastructure.”

We doubt that’s true of all the hundred-billion-plus in sanctions relief — and we know it’s not true of the ransom payout.

We doubt that’s true of all the hundred-billion-plus in sanctions relief — and we know it’s not true of the ransom payout.

As Bloomberg’s Eli Lake reported in June, the money — a settlement of Iranian legal claims dating back to 1981 — is going straight to the military.

The Foundation for the Defense of Democracies uncovered an item in Iran’s 2017 national budget ordering the Central Bank “to give the money from the legal settlement . . . of up to $1.7 billion to the defense budget” — which then rose 90 percent over the prior year’s.

In other words, the cash is being used to arm Iran’s terrorist clients, like Hezbollah, and to fund its war for Syria’s Bashar al-Assad.

Read the full story on the New York Post.