Former Democratic President Barack Obama has unloaded on Donald Trump for the Iran war , mocking the Republican president’s diplomatic strategy.

“These are not serious people. They’re not serious people. And the problem is you end up having to pay the price for their lack of seriousness,” Obama said Saturday while stumping for Democrats in Ohio .

The U.S., alongside Israel, started launching strikes against Iran in late February, with Trump claiming that Americans were in imminent danger over the Middle Eastern country’s nuclear ambitions.

But Obama argued that the issue had already been dealt with under his administration — until Trump unraveled it.

“Let’s think about this Iran war. The original rationale was, we’re going to go in there and get them to give up their nuclear program, their nuclear weapons,” Obama said. “Now, the thing was, Iran didn’t have nuclear weapons, because I put a deal in place that everybody acknowledged — kept them from getting nukes.…