I’m arriving tonight in Tehran, where I expect I’ll get a lot of interesting reaction to President Obama’s speech yesterday. (My own reaction was posted here, at length, yesterday.)

But I want emphasize one thing today: that by not mentioning “terror” or “terrorism” in his 55-minute address, Obama has formally turned the corner on the post-9/11 nightmare conjured by by President Bush and his ilk. If Obama sustains this, it has enormous potential not only to improve US relations with the Muslim world. It will utterly alter the discourse inside the United States, which for nearly eight long years has been distorted by the fear-mongering, Muslim-bashing, Osama-inflating, homeland security-worrying neoconservatives and their political allies.

As I pointed out yesterday, Obama stunned right-wing and centrist Israeli and pro-Israeli observers by referring with equanimity to Hamas, describing the Palestinian organization as having legitimate support among ordinary Palestinians and calling on Hamas to join the dialogue. A top Hamas official, Ahmad Yousef, an adviser to Ismail Haniya, the Hamas leader and prime minister, said:

“The things he said about Islam and the Palestinian suffering and their right to have a state is great. It is a landmark and a breakthrough speech.”

Now comes the test of Obama’s sincerity, in three immediate senses. We all get to taste the pudding and see if there is any proof in it.

The first test comes tomorrow in Lebanon, whose election will determine whether or not Hezbollah and its allies, including a chunk of Lebanon’s Christian bloc, gain a majority and will lead the new Lebanese government. The results won’t be known until Monday, at the earliest, and it’s a complicated, multi-confessional election that is certain to be marred by vote-buying, intimidation, and sectarian voting en bloc. But if Hezbollah and Co. win, it will be a severe test of Obama’s willingness to embrace political Islam. Were Obama to reject any contacts with a Lebanese government under a pro-Hezbollah majority, it will undo much of the positive spin in the Muslim and Arab media that has so far given Obama plaudits.

The second test comes June 12, in Iran. The election there pits President Ahmadinejad against two reformist rivals — ex-prime minister Mir Hossein Mousavi and cleric Mehdi Karrubi, a former speaker in parliament — and a conservative rival, Mohsen Rezai, a former commander of the Revolutionary Guard. The results there might not be known until after June 19, because if none of the four wins an outright majority, there will be a two-man runoff. If one of the reformists wins, it shouldn’t be hard for Obama to welcome his victory and renew his offer to sit down and talk. But, and here’s the test, if Ahmadinejad wins — with his radioactive rhetoric about the Holocaust and his defiant anti-Americanism — will Obama be able to reach out to Ahmadinejad and Ayatollah Ali Khamenei, the supreme leader, for talks? To do so will require Obama to sell the idea of talking to Ahmadinejad to a skeptical US public, already conditioned by Bush, the neocons, and yes, Hillary Clinton, into react in knee-jerk fashion to the Iranian firebrand. But talk we must. No doubt the Obama team is already trying to figure out how to sell that at home. I hope.

The third test, of course, involves Hamas itself. Rather than treat Hamas like it was carrying swine flu, Obama should encourage Egypt and Saudi Arabia — the two countries he just visited — to help put the Palestinian Humpty Dumpty back together in a new Fatah-Hamas unity government in advance of scheduled January elections. Announcing, as Bush did, that the United States will have no contact with such a coalition effectively undermines its very creation, since Hamas has no incentive to join one. Obama should gesture, ever more overtly, in support of exactly such a coalition. Yes, the Israeli right will go bananas.

But the neocons and the right, including the Republicans, are already denouncing Obama for undermining Israel, abandoning the holy democracy mission, and ending the Global War on Terror (GWOT). My favorite quote is from the always entertainingly stupid Michael Rubin, of the American Enterprise Institute, who foamed at the mouth over Obama’s de-emphasis of Project Impose Democracy. “Bush can look in the mirror and know that he liberated fifty million people,” wrote Rubin, neglecting to mention that Bush killed about a million of them in the process. “Obama will look in the mirror and admire how handsome he is.”

Well. Perhaps the pudgy Rubin can’t do the same when he gazes into his bathroom mirror. But the emerging apoplexy on Planet Neocon is a sign that Obama did something right in Cairo. Interesting, isn’t it, that with Hamas praising Obama, the only criticism of the Cairo speech is coming from (1) the neocons and their allies, and (2) Osama bin Laden, who is clearly panicking about Obama’s play for mainstream and conservative Muslim opinion. Strange bedfellows, indeed.