The stakes are high, not just for Israel but also for the wider Middle East, as tensions rise between Israel’s big ally, the United States, and their big foe, Iran. And they are very high for Netanyahu, too, as the outcome could determine whether or not he ends up behind bars.

Here’s what you need to know.

Why is there another election?

The last election for the Knesset, Israel’s legislature, took place in April. It resulted in a tie between Netanyahu’s right-wing Likud party and the relatively centrist, Gantz-led Blue and White alliance, which had just been formed for the occasion.

Likud had previously been able to turn to smaller right-wing and ultra-orthodox Jewish parties to support it in a governing coalition, along with the right-wing, secular Yisrael Beiteinu party of Avigdor Liberman. But not this time.

The argument centered on the military-service exemption that has always been granted to the country’s ultra-orthodox Jews. Netanyahu wouldn’t lift the exemption, so Liberman refused to join a new coalition. That meant Netanyahu couldn’t drum up the numbers he needed for a viable government—so back to the polls.

Who is Benny Gantz?

Netanyahu may be a hard-liner on the issue of Palestinian territory—the run-up to Tuesday’s election saw him promise to annex parts of the West Bank, and he very nearly launched a military operation in Gaza last week—but his opponent is no bleeding-heart liberal.

Gantz was the Israeli Defense Force’s chief of staff between 2011 and 2015—Netanyahu appointed him. On Iran, he has expressed a willingness to use force to contain Israel’s regional rival. He has also not launched any big arguments against the prime minister’s pre-election stance on the Palestinians, though he does appear to be more keen on achieving peace.

Instead, his campaign has focused on the corruption allegations against Netanyahu that could see the prime minister jailed—Gantz says his party won’t join any coalition government featuring Netanyahu. Centrists argue that, if Netanyahu retains power, the Knesset might vote to give him immunity in the corruption cases.

Gantz also wants to introduce term limits for prime ministers (Netanyahu has already had four) and to usher in civil marriages.

What about Trump?

Netanyahu has made much of his friendship with the U.S. president, with Likud showing both figures on its election banners.

Before the April election, Trump gave Netanyahu a significant boost by recognizing Israeli sovereignty over the Golan Heights, seized from Syria after the 1967 Six-Day War, and sending Secretary of State Mike Pompeo for a controversial photo-op with Netanyahu in Jerusalem’s Old City.

This time, Trump has only made non-committal noises about a defense pact between the two countries—which would be a risky move for Israel. The U.S. president also recently said he would be willing to meet with his Iranian counterpart. Again, that doesn’t do any favors for Netanyahu.

What do the polls say?

The last polls, released over the weekend, suggest that Likud and Blue and White will tie (or nearly tie) yet again, though this time each with fewer Knesset seats. Perhaps more importantly, it looks like neither the right nor the centrists will be able to form a coalition.

The question is, what happens next in that scenario? A third election is not outside the bounds of possibility, though voter fatigue would of course become more of an issue.

Exit polls will suggest the winner of Tuesday’s election late in the Israeli evening, though they have been wrong on both of the two most recent elections. So stay tuned for early Wednesday morning for the real results.

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