The United Nations General Assembly in New York. (Stsn Honda/AFP/Getty Images)

The annual United Nations General Assembly, in New York, is usually a pretty formulaic affair. Heads of state run through some diplomatic boilerplate, a few delegations might walk out in protest. At best, there might be an hour-long rant from a colorful dictator. But this year's General Assembly is shaping up to be different, and not just because there are fewer colorful dictators in the world.

Some contentious, high-stakes issues are set to play out in New York this week. The big one is the burgeoning game of footsie between the U.S. and Iran. There's also the war in Syria, global outrage against U.S. spying and a lot more. For once, what happens at the General Assembly could make a real difference. Here's a quick guide to eight of the biggest things to watch for.

1. Obama reaches out to Iran – while reassuring Israel

President Obama has a historic opportunity to finally realize his dream of detente with Iran, now that Iranians have elected the peace-minded moderate Hassan Rouhani as president. But Obama has a tough needle to thread here. In his speech to the assembly, he'll likely want to reciprocate Rouhani's outreach, reiterating his long-held position that the two countries can find a mutually acceptable grand bargain.

But Obama's also got to be mindful of Israeli Prime Minister Benjamin Netanyahu, who's expressed deep skepticism of Rouhani's gestures, which he views as a ploy to buy time for uranium enrichment. Obama will have to convince Israel, not to mention like-minded Iran hawks in Washington, to support his detente efforts, or at least to not veto them. Look for lots of language from him about how all options are on the table with Iran and how the U.S. will not tolerate a nuclear weapon or any threat to Israel.

Obama may also have to decide whether he wants to explicitly make the ongoing war in Syria, in which Iran plays a big role supporting Syrian leader Bashar al-Assad's forces, a component of any larger U.S.-Iran detente.

2. President Rouhani offers a new 'face of Iran'

One signal that Iranian voters sent in electing moderate cleric Hassan Rouhani this summer, as Washington Post correspondent Jason Rezaian has written, is that they're sick of Iran's international isolation and poor reputation. Rouhani has signaled that the days of former President Mahmoud Ahamdinejad's hard-line foreign policy and anti-Western rhetoric are over. In speech after speech, he's tried to convey a very different image, one of peaceful coexistence and diplomatic engagement with the world.

Whether Rouhani can succeed in reaching detente with the West – much less bringing along his boss, Supreme Leader Ali Khamenei – is not a question that will be answered this week. But he'll try to make a first step by changing the tone that Iran sets with the world, something he hinted at in comments on his Web site.

"Unfortunately in recent years the face of Iran, a great and civilized nation, has been presented in another way," he said in comments on his official Web site, according to a translation by Reuters. "I and my colleagues will take the opportunity to present the true face of Iran as a cultured and peace-loving country."

3. Will Obama and Rouhani meet?

Secretary of State John Kerry and Iranian Foreign Minister Javad Zarif are scheduled to meet on the sidelines of the General Assembly. That's a big deal in itself, a sign that both countries are moving toward direct talks for detente. It's also significant because Zarif authored Iran's 2003 offer of a "grand bargain" to the Bush administration, which rebuffed the outreach. Rouhani's decision to send Zarif to meet with Kerry sends the message, "let's try again."

Still, U.S. secretaries of state and Iranian foreign ministers have met before. What would be truly historic is having the nations' two presidents come together – which would be a first in the Islamic Republic's 34-year history. If they do meet, it will likely be officially unofficial – a highly choreographed "accidental" meeting, an opportunity to shake hands with no formal agenda.

4. Netanyahu cautions against Iran outreach – and may try to veto

At last year's General Assembly, the Israeli leader held up a drawing of a cartoon bomb with a big red line through it – a somewhat crude but attention-grabbing way of arguing to the world that Iran had crossed a "red line" in its nuclear program. His speech this year is expected to focus squarely, if perhaps only implicitly, on talking the United States out of softening its stance toward Tehran. Anticipate an urgent appeal for skepticism – and perhaps a case for U.S.-led military strikes against Iranian nuclear facilities.

5. Everyone makes their case on how to handle Syria

It's widely accepted at this point that Syria's civil war has also become something of a proxy conflict. The Syrian regime is backed by Iran and Russia; different rebel groups are supported by Turkey and Sunni Arab Gulf states; the United States also backs the rebels but wants a peace deal. And each of those countries has its own interests it's pushing in Syria.

Anticipate the heads of state of each of these countries, and perhaps the United Kingdom and France as well, to issue passionate and highly conflicting appeals on how to end the Syrian crisis. Many of those heads of state will claim to speak on behalf of the Syrian people, 100,000 of whom have died and 6 million of whom have been displaced since fighting started.

6. Russia's dilemma on Syrian chemical weapons

Russia's speech may be the most awkward of the assembly. Moscow continues to maintain that the Aug. 21 chemical weapons attack in Syria was the responsibility of Western-backed rebels – despite a recent United Nations report that did not formally assign blame but heavily implicated the Assad regime.

It will be interesting to see whether Russia retreats into defensive doubletalk, further pushing a pro-Assad line, or if it seeks to shore up the international leadership role it won with this month's chemical weapons proposal by taking a more measured approach.

7. This year's party crasher: the president of Sudan

Sudanese President Omar al-Bashir is wanted by the International Criminal Court for war crimes, including genocide. But he's avoided arrest for years by only traveling to countries that are friendly and/or are not signatories to the International Criminal Court. That also means avoiding events like the U.N. General Assembly.

So it was a surprise this year when Bashir requested a visa from the U.S. to come to New York for the General Assembly. He would be the first-ever head of state with a standing ICC arrest warrant to attend. The U.S. is in a bind with this; Obama administration officials have condemned Bashir's plan to visit, but it would be awfully awkward to block him given that the U.S. has long refused to sign on to the ICC. It will be interesting to see whether he's permitted to come, how he'll behave if he is permitted and what might happen if he's not – will one of Bashir's allies decry the United States at the lectern?

8. Brazil and others may knock the U.S. for NSA spying

Brazilian President Dilma Rousseff, who will open the General Assembly on Tuesday, made international headlines last week when she canceled a state dinner with Obama over her country's objections to NSA spying in Brazil. Leaders of other countries that are normally close with the United States, particularly Germany, have also raised public objections to U.S. spying programs.

Rousseff and other heads of state may raise U.S. spying in their speeches and they may not. Either way, Obama's reception will likely be a bit cooler than usual.