WHEN the long, grim history of Christianity’s disappearance from the Middle East is written, Ted Cruz’s performance last week at a conference organized to highlight the persecution of his co-religionists will merit at most a footnote. But sometimes a footnote can help illuminate a tragedy’s unhappy whole.

For decades, the Middle East’s increasingly beleaguered Christian communities have suffered from a fatal invisibility in the Western world. And their plight has been particularly invisible in the United States, which as a majority-Christian superpower might have been expected to provide particular support.

There are three reasons for this invisibility. The political left in the West associates Christian faith with dead white male imperialism and does not come naturally to the recognition that Christianity is now the globe’s most persecuted religion. And in the Middle East the Israel-Palestine question, with its colonial overtones, has been the left’s great obsession, whereas the less ideologically convenient plight of Christians under Islamic rule is often left untouched.

To America’s strategic class, meanwhile, the Middle East’s Christians simply don’t have the kind of influence required to matter. A minority like the Kurds, geographically concentrated and well-armed, can be a player in the great game, a potential United States ally. But except in Lebanon, the region’s Christians are too scattered and impotent to offer much quid for the superpower’s quo. So whether we’re pursuing stability by backing the anti-Christian Saudis or pursuing transformation by toppling Saddam Hussein (and unleashing the furies on Iraq’s religious minorities), our policy makers have rarely given Christian interests any kind of due.