It can cease supporting Israel's violation of International Law. It can insist it complies with UN Resolutions. It can cease all Aid to Israel until it returns within its legally recognised and agreed upon 1948 Borders. It can support International Intervention and insert an International Coalition to enforce Israel returning within its 1948 Borders. There is plenty America can do that it hasn't and the World knows it.
U.S., allies conduct 20 air strikes in Syria and Iraq against ISIS, says U.S. military (Reuters)
from the article: Why America is irrelevant to Middle East peacemaking