The full meaning of the ­recent war in the Caucasus was captured in a sad video of Armenians gathered outside an old mountain church to sing one last hymn before going into exile. This small Christian nation's humiliation at the hands of Azerbaijan and Turkey, two American allies, reveals the limits of US power and the need for a new strategy to aid Mideast Christians.

Once a majority, Christians find themselves stranded on shrinking demographic islands in Muslim-majority states that can't, and sometimes won't, protect them. The old advocacy model, the Western crusade, is obsolete and was never very effective anyway. Our new model -- human-rights lobbying -- is even less successful.

The story usually goes like this: A Christian population comes under attack, advocacy groups demand action from politicians, and politicians, though paying lip service to American values, ignore their request for fear of appearing biased or annoying local despots. There is a reason in their rhyme: The United States isn't, in fact, a Christian state, yet we advocates continue our work unhindered, year after year, hoping for a different result. Meanwhile, the Christian archipelago continues its slow slide into the sea of Muslim conquest.

It is worth noting that President Trump has done more for religious minorities than any president in history. Yet at no point during six weeks of war did he try to stop Azerbaijan and Turkey, let alone come to the aid of Armenians. His reasoning was simple: Foreign policy is about interests, and relations with powerful majorities will always trump the rights of weak minorities. Our advocacy fails because it chases government action that never materializes.

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That isn't to say American power is unimportant, especially when it comes to dealing with increasingly rogue states like Turkey. Whether bullying Greece, occupying Cyprus, invading Syria and Libya, bombing northern Iraq, supporting Hamas or inciting hatred against the West, Turkish strongman Recep Tayyip Erdogan seems eager to overtake the Iranian ayatollahs as the greatest threat to regional stability.

Putting moral arguments aside, our national interest demands that Washington move to contain Ankara's dreams of a new imperium. Yet even taming Erdogan's imperialist furies won't achieve our goal.

The only way to ensure a future for Mideast Christianity is to strengthen its economic foundations. A 2020 Philos Project survey of Palestinian Christians in the West Bank and Gaza found nearly half unable to meet daily needs; of the third that sought to immigrate, almost two-thirds cited financial reasons.

The situation is similar across the region. Long before ISIS destroyed Iraq and Syria, long before Hezbollah strangled Lebanon, centuries of economic decay had left Christians weak and exposed.

The time has come to shift our focus from state power to private investment, linking Christian businessmen in the West with those in the Middle East to open companies, develop properties and transport local products to market. This was the survival strategy of the early church, whose members pooled their wealth for the benefit of all. It demands more creativity and determination than today's model, but it promises more dignified and permanent results.

A peaceful economic crusade will prioritize Christian communities that have critical mass and favorable conditions for investment. Here, the significance of Armenia becomes obvious. Not only does Armenia rank high on the World Bank's Ease of Doing Business index, it also boasts an emerging high-tech sector and inexpensive yet skilled labor.

Its Christians have something that others in the region only dream of, political sovereignty, which amplifies any investment in three dimensions. A strong economy means greater engagement from potential allies and greater resilience against local enemies. It also turns Armenia into a safe haven for regional Christians looking for better opportunity and, if needed, emergency asylum among other indigenous believers.

It isn't too late to help Armenians, but our old approach of bullets and Band-Aids won't do. What we need is a groundswell of Western Christian concern translated into tangible investment. As an old Armenian proverb says, "Once we put shoulder to shoulder, we can turn mountains."

Robert Nicholson is president of the Philos Project, an organization that promotes serious Christian engagement with the Middle East.