Chabad of Port Washington, a Jewish community center on Long Island's Manhasset Bay, sits in a squat brick edifice across from a Shell gas station and a strip mall. The center is an unexceptional building on an unexceptional street, save for one thing: Some of the shortest routes between Donald Trump and Vladimir Putin run straight through it.

Two decades ago, as the Russian president set about consolidating power on one side of the world, he embarked on a project to supplant his country's existing Jewish civil society and replace it with a parallel structure loyal to him. On the other side of the world, the brash Manhattan developer was working to get a piece of the massive flows of capital that were fleeing the former Soviet Union in search of stable assets in the West, especially real estate, and seeking partners in New York with ties to the region.