MODESTO, Calif. — Isaac Samow's Assyrian Christian ancestors have occupied Mesopotamia for millennia, surviving innumerable conquests and massacres.

Now war is again threatening Assyrian culture and language in its native land.

Thousands of Assyrians have fled Iraq since the U.S. invasion. Samow's relatives are scattered through Canada, Australia, Denmark, New Zealand, Greece, Holland, England, Sweden and Germany. Other Assyrians are refugees in Syria, Jordan and inside Iraq, not knowing whether they can return to cities and towns carved into Sunni or Shiite enclaves.

"My children speak my language, but what about my grandchildren?" said Samow from his home in Modesto. "If there are no Assyrians left in Mesopotamia, how will our culture live?"

Successive waves of Assyrians have landed here in California's Central Valley, beginning with those who fled a massacre by Turks near the end of World War I.

They were joined by families who escaped Iran when an Islamic revolution overthrew the monarchy in 1979, then by new arrivals escaping the first Gulf War, when Samow, whose hometown is near Mosul, Iraq, came here with his family. An Assyrian community also thrives in Chicago.

But with their numbers now dangerously low in the region where Iran, Iraq and Turkey meet, Assyrians here fear the current wave of migration could mark their end. Community leaders in the United States are working to support Assyrians back home.

The Assyrian American Civic Club of Turlock is housed in a fortresslike hall decorated with winged bulls that have human heads — a traditional Assyrian protective figure known as a lamassus. An old map on the wall shows population centers that no longer exist.

"Once, most villages in that area were Assyrian," said the club's president, Fred Betmaleck, who is Iranian-Assyrian. "Now there are very few left."

The club works to keep Assyrian culture alive by hosting a radio station that plays Assyrian music, carries community news and holds festivals, such as the Assyrian New Year's celebration known as Kha-b-Nissan, in the spring.

Members also raised money through dances and raffles to help Assyrians who remain in Iraq.

"We try to help them stay there as much as possible, because when you leave, you never go back," said Betmaleck. "We encourage them not to come, but when there's persecution, what can you do?"

For Isaac Samow, staying was too risky.

He and his wife took their seven children — the youngest a 1-year-old whom Samow strapped to his back — on a dangerous hike across the rugged snow-covered mountains between Iraq and Turkey.

He spent all the money he'd saved from his job as a construction contractor to smuggle his family to the dirt-floor tents of a Turkish refugee camp, then to Istanbul. They spent a year and a half in Greece until they applied for asylum with Red Cross help and were accepted into the United States in December 1992.