The Graphic Truth: How NATO absorbed its old foes

For almost half a century, NATO and the Soviet-backed Warsaw Pact alliance glowered at each other across the Iron Curtain. But after the USSR collapsed, NATO expanded eastwards by welcoming former Eastern Bloc members – a development Moscow viewed as a direct challenge to its sphere of influence. This dynamic has become a massive point of contention recently, as Moscow increasingly threatens Ukraine's sovereignty. Russia wants assurances from Washington that states like Ukraine, Finland, and Sweden won’t join NATO. Here's a look at the history of the alliance's expansion.