The depression threat in America worries northern Europe more than the possibility of a Russian invasion, Senator Ralph E. Flanders declared last night in Littauer auditorium.

Flanders, delivering the second of three Godkin Lectures on "The American Century," spoke before an audience of about 100. His final talk, on the topic, "Pax Americans," will be delivered at 8 p.m. tonight in Litauer.

Europe's concern over America stems from the belief that it "would inevitably suffer" from a depression here, Flanders said last night. Such a recession, he commented, would help the Communist doctrine "take firmer root."

Since the U.S. cannot dodge foreign responsibilities, Flanders added, its objective should be the "material prosperity of the American citizen and the preservation of his freedom." This isn't really selfish, he said, because the United States could do little for others in a depression.

Flanders called the creation of spheres of influences by the United States unsatisfactory in the long run. "The tendency . . . has been to minimize the influence of our government and to maximize the mutual benefit of private trade."

Trade Treaties Backed

Reciprocal trade treaties were endorsed by Flanders as essential for "a more efficient world." He held reservations on the best application of the program and he proposed selling domestic groups at home.

At the same time, Flanders urged reciprocal trade with the protection of the "peril point" provision of the 80th Congress. "It was not wise," he said, "to eliminate it from the law passed by the 81st Congress."