International law says Putin's war against Ukraine is illegal. Does that matter?
- Written by Hurst Hannum, Professor of International Law, Fletcher School of Law & Diplomacy, Tufts University

Both international law and the United Nations Charter say that countries should not invade each other. But who has the ability to enforce those rules?
U.N. Secretary-General António Guterres put them to the test on...
Read more: International law says Putin's war against Ukraine is illegal. Does that matter?