What nation defeated Russia?

In the context of World War I, Russia was defeated primarily by the Central Powers, particularly Germany and Austria-Hungary, which led to the signing of the Treaty of Brest-Litovsk in 1918. In more recent history, Russia has faced significant military challenges, but it has not been definitively defeated by any single nation in a conventional war since the fall of the Soviet Union in 1991. However, conflicts like the Russo-Ukrainian War have seen Ukraine successfully repel Russian advances in certain areas.