Mubarak ruled for three decades. Among his victims were Coptic Christians, who make up around 10 percent of the population. They predate Islam, but today are a disadvantaged and increasingly threatened minority.

While the "government does not actively persecute or repress Christians, a prejudicial legal framework has created a permissive environment that allows Egyptian officials and private individuals to discriminate against Christians freely and with impunity," noted Michele Dunne of the Carnegie Endowment for International Peace.

The U.S. State Department reported that the regime "sometimes arrested, detained and harassed" those "whose beliefs and/or practices it deemed to deviate from mainstream Islamic beliefs and whose activities it alleged to jeopardize communal harmony."

Government-controlled media and government-funded mosques have encouraged violence. Converts are at particular risk.

Noted William Inboden of the Strauss Center for International Security and Law, "Egyptian converts from Islam to Christianity, though very few in number, have suffered particularly heinous treatment — including imprisonment and sadistic torture."

Equally disturbing, warned the U.S. Commission on International Religious Freedom (USCIRF), "violence targeting Coptic Orthodox Christians remained high." The Mubarak government rarely punished the attackers. Indeed, International Christian Concern noted that it was common for the government to arrest "Coptic victims alongside the perpetrators of the violence."

It's no surprise that failing to exact a penalty for murder and mayhem led to what the Hudson Institute's Nina Shea called "pogroms and acts of terror."

Dina Guiguis of the Washington Institute for Near East Policy told a recent congressional hearing that "the Egyptian regime is fully responsible for creating the fertile ground on which pernicious and egregious sectarian violence has become routine." Those who hoped the Egyptian revolution would better protect Christians and other religious minorities have been disappointed. To the contrary, violent attacks on Copts have been increasing.

As of June, 24 Christians had been killed, more than 200 had been injured, and three churches had been destroyed. Muslim mobs beset Coptic churches, businesses, and homes. Well-armed thugs also have attacked Christians who were protesting against earlier attacks. Few perpetrators have been arrested, let alone punished.

Noted Paul Marshall of the Hudson Institute: "As under Mubarak, the authorities' refusal to punish attacks on Christians has led to more attacks."

The army even has assaulted two Coptic monasteries, supposedly to enforce discriminatory zoning laws (which prohibited walls erected for protection from attacks).

Complained the Commission: "Since Feb. 11, military and security forces reportedly have used excessive force and live ammunition targeting Christian places of worship and Christian demonstrators. Implementation of previous court rulings — related to granting official identity documents to Baha'is and changing religious affiliation on identity documents for Christian converts — continues to lag.

In addition, the government has not responded adequately to combat widespread and virulent anti-Semitism in the government-controlled media."

Islamic extremists are responsible for what increasingly looks to be a campaign of intimidation. The World Evangelical Alliance's Religious Liberty Commission explained that the attacks have been "mostly incited by conservative Salafi Muslims," who are using violence to mobilize Islamist support.

Nina Shea fears "what we're seeing in Egypt today — namely, a reinvigorated effort by some of the country's more radical Islamists to establish Egypt's identity as a thoroughly Islamicized and Arabicized state." The Copts "are the most visible bloc standing in the way of impatient jihadists and violent Salafis," who are accelerating their attacks.

The future looks bleak. Although there has been some pushback — Muslims rallied to help rebuild one of the destroyed churches — the vast majority of Egyptians express intolerance toward minority faiths. Shea worries about "a mass exodus" of Copts from Egypt if existing trends continue.

Unfortunately, international influence is limited. The USCIRF recommended that Washington designate Egypt a "country of particular concern, which, if adopted by the State Department, could lead to a variety of penalties. Religious liberty also should be part of the U.S. government's official dialogue with Egyptian authorities.

Religious extremism acts as an efficient incubator for violence. If the radicals grow in influence, they might destroy any new democratic political system.

As Georgetown's Thomas Farr recently testified before the U.S. Congress: "There will be no real freedom in Egypt — period — and there will be no real stability in Egypt — period-unless there is full religious freedom in Egypt, not only for its Coptic minority but also for moderate and reformist Muslim voices."

The Arab Spring risks turning into the Islamist Winter. The willingness to safeguard religious liberty has become a proxy for measuring the impact of the ongoing revolution. As go the Copts may ultimately go the rest of the Middle East.

Doug Bandow is a senior fellow at the Cato Institute and the senior fellow in international religious persecution at the Institute on Religion and Public Policy. A former special assistant to President Ronald Reagan, he is author of "Beyond Good Intentions: A Biblical View of Politics" (Crossway).