Scott Walker just announced that he's running for president in 2016. He's the 15th Republican candidate, so he's kind of late to the party, but he's definitely the first presidential hopeful to claim that union busting in Wisconsin has trained him to lead the fight against the Islamic State.

"If I can take on 100,000 protesters, I can do the same across the world."

That's how Walker answered a question about the Islamic State at the Conservative Political Action Conference in late February, and it still ranks up there as one of the worst foreign policy gaffes of the long campaign season. (Although, at this point, it would be hard to top Donald Trump's comments about Mexican immigrants being rapists.)

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Sure, it was just one terribly worded, terribly thought-out sentence, but by the time Walker let those words come out of his mouth, he'd already developed a reputation for being uninformed about foreign policy, national security, and the world.

It's no wonder, considering exchanges like the one he had with ABC News Chief Global Affairs Correspondent Martha Raddatz on ABC's "This Week."

RADDATZ: Let’s talk about some specific, and you talk about leadership and you talk about big, bold, fresh ideas. What is your big, bold, fresh idea in Syria? WALKER: Well, I think — I go back to the red line. RADDATZ: Let’s not go back. Let’s go forward. What is your big, bold idea in Syria? WALKER: I think aggressively, we need to take the fight to ISIS and any other radical Islamic terrorist in and around the world, because it’s not a matter of when they attempt an attack on American soil, or not if I should say, it’s when, and we need leadership that says clearly, not only amongst the United States but amongst our allies, that we’re willing to take appropriate action. I think it should be surgical. RADDATZ: You don’t think 2,000 air strikes is taking it to ISIS in Syria and Iraq? WALKER: I think we need to have an aggressive strategy anywhere around the world. I think it’s a mistake to — RADDATZ: But what does that mean? I don’t know what aggressive strategy means. If we’re bombing and we’ve done 2,000 air strikes, what does an aggressive strategy mean in foreign policy? WALKER: I think anywhere and everywhere, we have to be — go beyond just aggressive air strikes. We have to look at other surgical methods. And ultimately, we have to be prepared to put boots on the ground if that’s what it takes, because I think, you know — RADDATZ: Boots on the ground in Syria? U.S. boots on the ground in Syria? WALKER: I don’t think that is an immediate plan, but I think anywhere in the world. RADDATZ: But you would not rule that out. WALKER: I wouldn’t rule anything out. I think when you have the lives of Americans at stake and our freedom loving allies anywhere in the world, we have to be prepared to do things that don’t allow those measures, those attacks, those abuses to come to our shores.

Walker, you'll noticed, couldn't even keep his clichés straight, much less offer a "big, bold, fresh idea in Syria."

The Wisconsin governor wrapped up his disastrous February — which included a widely panned trip to London where he refused to answer questions related to foreign policy — with an address at the Club for Growth, where he claimed that "the most significant foreign policy decision" of his lifetime was Ronald Reagan's decision to fire 11,000 air traffic controllers to break a strike in 1981.

"It sent a message not only across America," he explained, "it sent a message around the world."

"It would be a foolish approach to take, and perhaps Mr. Walker — after he's taken some time to bone up on foreign policy — will feel the same way."

And that's how Walker found himself in months of policy boot-camp.

The results have been mixed.

On the plus side, he and his team have nailed down the foreign policy portion of his stump speech, which goes something like this:

"This president drew a line in the sand and allows people to cross it, who called ISIS the JV squad, who calls Yemen a success story, who calls Iran a place we can do business with. As a kid, I can remember tying yellow ribbons around our tree out front because for 444 days, Iran held Americans hostage. Iran has not changed much. We need a commander in chief who's going to look the American people in the eye and tell them exactly what's at stake here: Radical Islamic terrorism is a threat to us all, and we're got to do something to stop it before they take the fight to us. We need a president who understands that Israel is an ally and start acting like it. And we need a president who's going to have the courage to look the American people in the eye and tell them what might not be easy to say, because it's not going to take a day, a week, a month, or even a year, but our enemy was not like the one we grew up with in the Cold War, when containment was enough. This is like a virus. If you don't take it out, it will only come back stronger. I'd rather take the fight to them than wait till they bring it to us."

That should do the trick with friendly audiences, but it's not clear how well he'll manage off the stump. And, at some point he'll need to present his own vision, and not just criticize Obama's.

And there have been more missteps and miscalculations since his messy February. In late March, he said unequivocally during a radio interview that on "Day One" of his presidency he'd revoke an Obama administration nuclear deal with Iran.

President Obama was about as dismissive of Walker as you could imagine a sitting president being toward a presidential candidate.

"It would be a foolish approach to take," he said on NPR, "and perhaps Mr. Walker — after he's taken some time to bone up on foreign policy — will feel the same way."

(The Walker campaign responded with a statement that rehashed the key talking points from his stump speech.)

Walker also tried to beef up his foreign policy credibility by visiting Israel in May. Again, it was mixed. He managed to avoid a repeat of his embarrassing London trip — but only because he refused to take questions from the press. It was a "listening tour," he said.

Last (for now), there's Walker's odd insistence on rebranding "national security" issues as "safety" issues. He's variously described "national security" as a phrase you'll hear from "some in Washington" or something you "read about in the newspaper." "Safety," on the other hand is "something you feel in your heart."

It's obvious what Walker's trying to do here. He's re-framing national security, defense, foreign policy, and counterterrorism in language usually reserved for local concerns like policing. As a governor, he's got experience in "safety," but none in "national security," so it would be convenient if they were more or less the same thing.

It might work on the stump, but his folksy turn-of-phrase might be a bit too reminiscent of Sarah Palin's attempts in 2008 to argue that Alaska's proximity to Russia means her executive experience was also foreign policy experience.

So Walker's got a long way to go when it comes to foreign policy chops.