President Bush’s wave of democracy is sweeping the Middle East, but it simply does not figure that the forces of despotism and darkness are going to yield without a fight.

The counterattack may have begun with Hezbollah’s mass demonstration in Beirut on Tuesday. Presumably, it won’t stop there. Hezbollah has up to 20,000 men with arms. It blew up the U.S. Marine barracks and the U.S. Embassy in Lebanon in 1983 and drove Israeli forces to leave Southern Lebanon.

Moreover, as a terrorist group, the “Party of God” has global connections and global reach. It is aided and funded not only by Syria but also Iran. Hezbollah killed 19 U.S. Air Force personnel in a bombing at the Khobar Towers apartment complex in Saudi Arabia in 1996.

It also bombed the Israeli Embassy in Buenos Aires, Argentina, in 1992 and a Jewish community center there in 1994. It plotted an attack on Israeli targets in Singapore in the 1990s. In 2002, two men were convicted in North Carolina of smuggling cigarettes to raise funds for Hezbollah.

Around the world, “security services are not cracking down forcefully and not paying attention to the terrorist cells and networks that are being established internationally right under the respective authorities’ noses,” said Matthew Levitt, a scholar at the pro-Israel Washington Institute for Near East Policy.

“The mistakes that are now being made regarding Hezbollah are the same as those made a decade ago concerning al Qaeda.”

It’s increasingly, and gratifyingly, clear, as Bush said on Tuesday, that “across the Middle East, a critical mass of events is taking that region in a hopeful new direction.”

In Afghanistan, Iraq, Palestine and Lebanon — and even, to an extent, in Egypt, Saudi Arabia and Iran — “it should be clear that authoritarian rule is not the wave of the future; it is the last gasp of a discredited past.”

Is it Bush’s doing? In many quarters — though not widely, as yet, in the Democratic Party — Bush is getting credit. His most improbable endorsement came from Walid Jumblatt, the Lebanese Druze leader who has not always been so friendly to the United States.

He told The Washington Post, “It’s strange for me to say it, but this process of change has started because of the American invasion of Iraq. I was cynical about Iraq. But when I saw the Iraqi people voting three weeks ago, eight million of them, it was the start of a new Arab world. The Syrian people, the Egyptian people, all say that something is changing. The Berlin Wall has fallen. We can see it.”

It’s true, as some Bush critics say, that it was Iraq’s Ayatollah Sistani who insisted, over the United States wavering, that his country’s Jan. 30 elections be held on time. But those elections would not have been possible without Bush’s decision to topple Saddam Hussein.

It’s also true that Bush’s initiative has been expensive, particularly in lost lives, both American and Iraqi. But, if all of this really produces a democratic Middle East, Americans surely will find it worthwhile. Bush will go down with the late Ronald Reagan as a historic American president.

But we’re not there yet, either on the ground or in the mind of the American public. The latest Fox News poll asked, “With George W. Bush as president, do you think the world is generally heading in a better direction or a worse direction?” The answer was, “better,” 41 percent, “worse,” 43 percent.

But if the progress toward freedom continues and Bush gets credit for it, those numbers will change. And chances are, Democratic doubters will be swamped in the process.

So too the Republican “realists,” who never believed that democracy could prevail in the Mideast — or even in Eastern Europe, for that matter — and that “stability” was the best goal of U.S. foreign policy.

The “Bush Doctrine” holds that the way to fight terrorism, and, to build support for the United States, is for this country to support the popular yearning for self-government and prosperity and to oppose authoritarianism, even when it’s practiced by ostensible U.S. allies like Egypt’s Hosni Mubarak and the Saudi Royal family.

But there remain three big obstacles to the triumph of the Bush Doctrine.

One is the sheer difficulty of embedding democracy in Middle East cultures that have never known it.

The second is the possibility that democracy will be short-lived, as it has been in Russia, with popular rule quickly giving way to renewed dictatorship, and possibly Islamic extremism.

And the third is the resistance of those who have everything to lose if democracy succeeds.

In Iraq, those forces, Saddamists and Islamists, are committing mayhem every day to prevent a stable government from taking hold.

It’s hard to believe that Syria, Iran and the terrorist forces they aid — Hezbollah, al Qaeda, Islamic Jihad, Hamas and the rest — will let themselves be blown away by the forces of freedom.

Under pressure from the Lebanese population and the world community, Syria is hoping that it can get away with a redeployment of its forces in Lebanon, not a total withdrawal. It’s hoping that Hezbollah’s demonstrations will be taken as a sign that Lebanese Shiites, at least, don’t want full withdrawal.

Fortunately, that’s not likely to work. France, Saudi Arabia and the United Nations are joining the United States in calling for a full withdrawal. And foreigners have the power to inflict serious damage on Syria’s decrepit economy if it does not comply.

Hezbollah may not be able to keep Syrian forces in Lebanon. But it could try by staging attacks against Israel, hoping that retaliation might divert the world’s pressure. Bush seemed to be trying to pre-empt such a tactic by pointing out Tuesday that the latest terror bombing in Tel Aviv was carried out by a radical Palestinian group headquartered in Damascus.

It will be a major test of international resolve whether Europe and the United Nations join the United States in demanding Hezbollah’s disarmament. So far, Europe does not list Hezbollah as a terrorist group.

Conceivably, Hezbollah might “go political”— compete in Lebanon’s May elections, bid to become the single most influential party in the country’s parliament and, ultimately, try to turn Lebanon into an Islamic state allied with Iran and at war with Israel.

Under Bush, the most powerful nation on earth is at last fully committed to the cause of freedom. It is a historic act of leadership. It is making a difference. But freedom has enemies. They have weapons. Before this fight is over, they are likely to use them.