President Obama speaks in June about the deteriorating situation as ISIS militants move toward Baghdad after taking control of northern Iraqi cities. (Win McNamee/Getty Images)

Americans approved of President Obama's decision to launch airstrikes in Iraq and now strongly approve of his plan to expand into Syria the effort to combat the Islamic State.

And yet, Obama's approval rating on foreign policy remains a dismal 34 percent in a new NBC/Wall Street Journal/Annenberg poll released Sunday. That's even as the survey shows Americans approve of Obama's Middle East plan by an overwhelming margin, 66 percent to 22 percent.

So why can't Obama catch a break? Put plainly: People just don't think he'll succeed.

The poll shows a striking lack of confidence when it comes to the situation in the Middle East. About two-thirds of people (68 percent) have "very little" or "just some" confidence in Obama's stated goal of "degrading" and "destroying" the Islamic State. An additional 28 percent say they have "a great deal" or "quite a bit" of confidence in Obama.

This vote of no/little confidence, without a doubt, owes in part to the tough situations in the two Middle Eastern counties the United States has attempted to stabilize over the past decade: Afghanistan and Iraq. Given those experiences, it's not surprising that Americans would be pessimistic about succeeding against the Islamic State.

But Obama's persistently low approval rating on foreign policy suggests that it's also in large part because people doubt he's up to the task. Polls have repeatedly shown that people don't think Obama is tough enough. This is an extension of that.

On the plus side for Obama, 26 percent of Americans said his speech on Wednesday night gave them a more favorable impression of him, while 20 percent said they came away with a less favorable one.

But Obama has never really struggled with giving good speeches; he has struggled with getting people to believe in him.