As Russia and the United States prepare to meet in Saudi Arabia to discuss Russia’s invasion of Ukraine, there’s a notable absence: Ukraine, which was purposely sidelined from negotiations. History shows that’s a really bad idea, which contributed to losses in Vietnam and Afghanistan.

In 1972, North Vietnam’s “Easter Offensive” turned into a disaster for the invaders. Four years after the Tet Offensive, they were no closer to taking South Vietnam than they were in 1968. But all along, there were secret meetings between the National Security Advisor Henry Kissinger and the North Vietnamese negotiator Le Duc Tho outside the Paris Peace Talks.

John A. Tures is a professor of political science at LaGrange College in Georgia. He can be reached at jtures@lagrange.edu. His Twitter account is @JohnTures2.