At the NATO summit in Vilnius, Lithuania, Turkey agreed to support Sweden’s bid to join the alliance. This paves the way for Sweden to become the 32nd member nation following closely behind Finland, which became a member earlier in the spring. The expansion of NATO is something Russia and President Vladimir Putin have used as a key rationale for the war against Ukraine – saying it jeopardizes Russia’s security.Timothy Sayle is an associate professor of history and director of the International Relations Program at the University of Toronto. He’s also the author of Enduring Alliance: A History of NATO and the Postwar Global Order. He’s on the podcast to explain the history and tension between NATO and Russia and what more countries joining the alliance tells us about the current state of global affairs.Questions? Comments? Ideas? E-mail us at thedecibel@globeandmail.com