In Donald Trump’s opinion, his opposition to the Iraq War is a measure of his foreign policy foresight.

"As you know and as everyone knows, I was against the war in Iraq," Trump said Sunday on CBS’s Face The Nation in a joint interview with running mate Indiana Gov. Mike Pence. "I was totally against it, because I said it would destabilize the Middle East. And it has. That's exactly what has happened. It was a very bad decision."

But there are a couple of problems with this line of attack. For starters, there doesn’t seem to be any evidence that Trump actually opposed the war before it began in March 2003. Also, Trump’s running mate, Indiana Gov. Mike Pence, cast the same pro-war vote in 2002 as Trump’s opponent, Hillary Clinton.

But in a forgiving moment Sunday, Trump admitted he "didn’t care" his running mate voted for the Iraq War. "He’s entitled to make a mistake every once in a while," Trump said.

As for Hillary Clinton, she didn’t get the same lenience. Asked why she isn’t entitled to a mistake, Trump simply said "she’s not." And that was that.

Here is the exchange:

Lesley Stahl: But we did go to war, if you remember. We went to Iraq. Donald Trump: Yeah, you went to Iraq, but that was handled so badly. And that was a war — by the way, that was a war that we shouldn't have entered because Iraq did not knock down — excuse me — Lesley Stahl: Your running mate — Donald Trump: Iraq did not — Lesley Stahl: — voted for it. Donald Trump: I don't care. Lesley Stahl: What do you mean you don't care that he voted for? Donald Trump: It's a long time ago. And he voted that way and they were also misled. A lot of information was given to people. Lesley Stahl: But you've harped on this. Donald Trump: But I was against the war in Iraq from the beginning. Lesley Stahl: Yeah, but you've used that vote of Hillary's that was the same as Gov. Pence as the example of her bad judgment. Donald Trump: Many people have, and frankly, I'm one of the few that was right on Iraq. Lesley Stahl: Yeah, but what about he — Donald Trump: He's entitled to make a mistake every once in a while. Lesley Stahl: But she's not? Okay, come on — Donald Trump: But she's not — Lesley Stahl: She's not? Donald Trump: No. She's not. Lesley Stahl: Got it.

Trump and Pence should probably have a good answer for this one

In October 2002, President George W. Bush sought authorization from Congress to invade Iraq, a country that he claimed was making significant progress toward building a nuclear weapon (a claim that was later found to be untrue). Still riding a wave of popularity in the wake of the previous year’s September 11 attacks, Bush put a lot of pressure on members of Congress to support the war.

Then-Sen. Hillary Clinton voted yes. So did then-Rep. Mike Pence.

Donald Trump has made this vote a centerpiece of his foreign policy argument against Clinton.

"It all started with her bad judgment in supporting the war in Iraq in the first place," Trump said in his anti-Clinton speech in late June.

And when Clinton attacks Trump on foreign policy, his first line of defense is, again, his opposition to the Iraq War.

"I see the ads on foreign policy, [Clinton] talking about Donald Trump doesn’t have foreign policy experience. Of course not; I have been a very, very successful business person," Trump said in his VP announcement Saturday. "But if you look at my calls, I said don’t go into Iraq, but nobody cared because I was a businessman, I was a civilian."

But Trump has yet to provide evidence that he did, in fact, oppose the Iraq War before it started. Politifact looked into Trump’s claim and rated it "false." "We could only find one example of Trump commenting on the Iraq War before the invasion where he seemed apprehensive but not vehemently opposed to the operation," Politifact reported. "In another interview, Trump said he supported the invasion."

Choosing Pence as his running mate is going to make it even harder for Trump to prosecute this line of attack against Clinton.