President Trump is expected to announce whether the United States will remain in the Iran nuclear deal this afternoon — though, it seems likely he will choose to withdraw — but most Americans simply don't know enough to have an opinion about the decision, according to new polling.

The bottom line: Trump's decision on Iran will be one of the most significant foreign policy moments of his presidency thus far and risks isolating the U.S. from its allies in Europe. However, per CBS News, more than half of Americans "don't know enough" to evaluate his choice and, per Pew Research, a quarter of Americans have heard "nothing at all" about the deal.

• And according to another poll from CNN/SRS, which did frame its question with a clear "don't know" option: 63% think the U.S. should remain in the deal while 29% believe it should withdraw.

A smart take on the topic, from The Huffington Post's polling editor, Ariel Edwards-Levy, who addressed the Pew and CNN results:

More top-line numbers

From Pew:

• Only 27% of Americans say they've heard "a lot" about the Iran nuclear deal, 46% say they have heard "a little," and 26% say they've heard "nothing at all."
• 40% say they disapprove of the deal, 32% approve, and 28% have no opinion.
• 34% of Americans say they are not confident at all in Trump's handling of the situation with Iran and 18% are not too confident. On the flip side, 24% are very confident and 16% are somewhat confident.

From CBS News:

• 57% of those surveyed say they "don't know enough" about the deal.
• Among those who said they do know enough: 21% said the U.S. should remain in the deal and 21% said the U.S. should leave the deal.

Don't know yourself? Learn the details behind the Iran nuclear deal.