As the governor of Wisconsin, Republican Scott Walker hasn’t had to deal much with foreign policy. That’s not his fault, of course – governors have plenty of important responsibilities, but foreign affairs aren’t among them – but now that Walker is poised to become a leading GOP presidential candidate, he’ll have to demonstrate some working understanding of the world.

He certainly seems eager to try. A Republican operative recently lobbed comically easy questions at Walker, such as, “You command the [Wisconsin] National Guard. I wondered if you might want to comment on how you feel about the threat posed by ISIS and other entities abroad?” Walker responded by delivering a lengthy, and probably rehearsed, answer about his extensive work on matters of national security, including classified briefings from FBI officials.

On ABC’s “This Week” yesterday, Martha Raddatz approached the same issue, but without the softballs.

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?

The Wisconsin governor responded that U.S. must have “an aggressive strategy,” prompting the host to ask what many of us were thinking: “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?”

At this point, it apparently occurred to Walker that meaningless sound bites and catchphrases weren’t going to cut it.

So the governor shifted a bit, arguing that U.S. officials should be “prepared to put boots on the ground.” Asked if he meant ground forces in Syria, Walker responded, “I don’t think that is an immediate plan…. I wouldn’t rule anything out.”

The exchange prompted Laura Rozen to note , “Scott Walker does not seem very ready for prime time.”

Every White House hopeful goes through a learning process, and Walker wouldn’t be the first governor who struggled with foreign policy as his campaign got underway. The bigger problem is that the Wisconsin Republican doesn’t have a strong suit to lean on when the international questions get tough. His record in his home state probably won’t help

One of his biggest applause lines [in Iowa last week] was his mention that Wisconsin requires photo identification before voting. That’s true, but Walker didn’t mention that the requirement has been blocked by the U.S. Supreme Court and may never be enforced. Walker boasted about the “big and bold” tax cuts on his watch – $2 billion in savings for individuals and businesses – without mentioning the projected $2.2 billion budget shortfall Wisconsin faces in the coming two years.

The governor would be in even more trouble if he tried to turn to his attention to job creation, which has arguably been Walker’s worst issue