Apparently technology hasn’t advanced much under Islamic rule, either. Characters still zip around in automobiles today’s Americans would recognize, and their high-tech equipment isn’t really much more high tech than our iPods. Satellites from the “old regime” are beginning to degrade, and new ones haven’t been launched. Many roads are impassible, and medieval-style gangs often attack unwary travelers. All the best equipment comes from China (believable) and Russia (not so believable). American ingenuity is sorely missed.

Ferrigno paints a compelling picture, but some important questions are unanswered. Most critical is, “How did we get there from here?”

He says the wave of conversions actually started before the 2015 attacks, when an Oscar-winning actress announced her conversion during her acceptance speech. All well and good, but if Hollywood stars actually carried that much weight, most of the country would have converted to Scientology by now. Tom Cruise’s religion must be at least as likely to catch on as Islam would be.

It’s also unclear what keeps the peace along the giant border between the two competing versions of the United States. Major battles in Newark and Chicago are mentioned -- but why no fighting near Louisville?

Those quibbles aside, Ferrigno does make several astute observations. A Seattle cop mentions that under the former government, artists were actually paid tax money to dip crucifixes in urine. Such blasphemy, he notes, would never happen under the 2040 regime.

Also, San Francisco under Islamic rule is a fundamentalist hotbed. Homosexuals are frequently executed there -- a development that might not surprise another author, Bruce Bawer, a homosexual now living in Europe.

His latest book is “While Europe Slept: How Radical Islam is Destroying the West from Within.” As Bawer wrote on his Web site, “If fundamentalist Muslims in Europe do not carry out these punishments (executing homosexuals), it is not because they’ve advanced beyond such thinking, but because they don’t have the power.” In “Assassin,” Ferrigno anticipates the Islamic takeover of the continent by noting that as far back as the 1970s, a clever leader encouraged Muslims to emigrate to, but not to integrate with, Europe.

Anything can happen between now and 2040. It seems unlikely that the United States we turn over to our children will be an Islamic republic. But “Prayers for the Assassin” is good read and a timely warning of what could happen unless we’re careful. Since, as Jefferson said, “The price of freedom is eternal vigilance.”