LONDON ― The announcement, following the use of chemical weapons in Syria, of an emergency summit in Jordan this week of military leaders from the United States, the United Kingdom, France, Germany, Italy, Canada, Turkey, Saudi Arabia, and Qatar is a welcome development. Western policy is at a crossroads: commentary or action; shaping events or reacting to them.

After the long and painful campaigns in Iraq and Afghanistan, I understand every impulse to stay clear of the turmoil, to watch but not to intervene, to ratchet up language but not to engage in the hard, even harsh business of changing reality on the ground. But we have to understand the consequences of wringing our hands instead of putting them to work.

People wince at the thought of intervention. But contemplate the future consequences of inaction and shudder: Syria, mired in the carnage between the brutality of Bashar al-Assad and various affiliates of Al Qaida, a breeding ground of extremism infinitely more dangerous than Afghanistan in the 1990’s; Egypt in chaos, with the West, however unfairly, looking as if it is giving succor to those who would turn it into a Sunni version of Iran; and Iran itself, despite its new president, still a theocratic dictatorship, with a nuclear bomb. The West would appear confused, its allies would be dismayed, and its enemies would be emboldened. This is a nightmare scenario, but it is not far-fetched.

Start with Egypt. To many in the West, it is clear that the Egyptian military has removed a democratically elected government and is now repressing a legitimate political party, killing its supporters and imprisoning its leaders. So we are on a steady track toward ostracizing the new government. In doing so, we think that we are upholding our values. I completely understand this view. But to embrace it would be a grave strategic error.

The fallacy of this approach lies in the Muslim Brotherhood’s nature. We think of it as a normal political party. It is not. If you want to join the U.K. Conservative Party or the German Christian Democrats or America’s Democratic Party, you can do so easily, and they will welcome you with open arms. In all of these countries, all parties respect basic democratic freedoms.

The Muslim Brotherhood is not such a party. Becoming a member is a seven-year process of induction and indoctrination. The Brotherhood is a movement run by a hierarchy that is more akin to the Bolsheviks.

Read their speeches ― those put out not for Western ears, but for their own. What they were doing in Egypt was not “governing badly.” If you elect a bad government, then tough ― you live with it. The Muslim Brotherhood, by contrast, was systematically changing the constitution and taking control of the commanding heights of the state in order to make it impossible for its rule to be challenged. And it was doing so in pursuit of values that contradict everything for which democracy stands.

So you can rightly criticize the actions or overreactions of Egypt’s new military government; but it is difficult to criticize the intervention that brought it into being. Now all of the choices that Egypt faces are ugly. There are large numbers of soldiers and police among the casualties, as well as civilians; and, partly as a byproduct of the fall of Libya’s Muammar el-Gadhafi, Egypt is awash with weapons. But simply condemning the military will not bring a return to democracy any nearer.

Egypt is not a creation of nineteenth- or twentieth-century global power games. It is an ancient civilization stretching back thousands of years, imbued with fierce national pride. The army has a special place in its society. The people do want democracy, but they will be disdainful of Western critics whom they will see as utterly naive in the face of the threat to democracy that the Muslim Brotherhood posed.

We should support the new government in stabilizing the country; urge everyone, including the Muslim Brotherhood, to get off the streets; and let a proper and short process to an election with independent observers be put in place. A new constitution that protects minority rights and the basic ethos of the country should be drafted, and all political parties should operate according to rules that ensure transparency and commitment to the democratic process.

This is the only realistic way to help those ― probably a majority ― who want genuine democracy, not an election used as a route to domination.

In Syria, we know what is happening ― and that it is wrong to let it happen. But leave aside any moral argument and just think of the world’s interests for a moment. Doing nothing would mean Syria’s disintegration, divided in blood, with the countries around it destabilized and waves of terrorism rolling over the region. Assad would remain in power in the richest part of the country, with bitter sectarian fury reigning in the country’s eastern hinterland. Iran, with Russia’s support, would be ascendant ― and the West apparently impotent.

I hear people talk as if nothing can be done: the Syrian defense systems are too powerful, the issues too complex, and in any event, why take sides when one is as bad as the next?

But others are taking sides. They are not terrified of the prospect of intervention. They are intervening in support of a regime that is assaulting civilians in ways not seen since the dark days of Saddam Hussein.

It is time we took a side: the side of the people who want what we want; who see our societies, for all their faults, as something to admire; who know that they should not be faced with a choice between tyranny and theocracy. I detest the implicit notion behind so much of our commentary that the Arabs or, even worse, the people of Islam, are unable to understand what a free society looks like, that they cannot be trusted with something so modern as a polity where religion is in its proper place.

It is not true. What is true is that there is a life-and-death struggle going on over the future of Islam, with extremists aiming to subvert both its open-minded tradition and the modern world.

In this struggle, we should not be neutral. Wherever this extremism is destroying the lives of innocent people ― from Iran to Syria, Egypt, Libya, and Tunisia, as well as elsewhere in Africa, Central Asia, and the Far East ― we should be at their side.

As one of the architects of policy after the terror attacks of Sept. 11, 2001, I know the controversy, anguish, and cost of the decisions taken. I understand why the pendulum has swung so heavily the other way. But it is not necessary to revert to that policy to make a difference. And the forces that made intervention in Afghanistan and Iraq so difficult are of course the very forces at the heart of the storm today.

They have to be defeated. We should defeat them, however long it takes, because otherwise they will not disappear. They will grow stronger, until we will reach another crossroads; at that point, there will be no choice.

By Tony Blair

Tony Blair, prime minister of the United Kingdom from 1997 to 2007, is special envoy for the Middle East Quartet. ― Ed.

(Project Syndicate)