Eight Lessons from the Ukraine War

When Russian President Vladimir Putin ordered his invasion of Ukraine on February 24, he envisaged a quick seizure of Kyiv and a change of government analogous to Soviet interventions in Budapest in 1956 and Prague in 1968. But it wasn't to be. The war is still raging, and no one knows when or how it will end.

While some observers have urged an early ceasefire, others have emphasized the importance of punishing Russian aggression. Ultimately, though, the outcome will be determined by facts on the ground. Since it is too early to guess even when the war will end, some conclusions are obviously premature. For example, arguments that the era of tank warfare is over have been refuted as the battle has moved from Kyiv's northern suburbs to the eastern plains of the Donbas.

But even at this early stage, there are at least eight lessons – some old, some new – that the world is learning (or relearning) from the war in Ukraine.

First, nuclear deterrence works, but it depends on relative stakes more than on capabilities. The West has been deterred, but only up to a point. Putin's threats have prevented Western governments from sending troops (though not equipment) to Ukraine. This outcome does not reflect any superior Russian nuclear capability; rather, it reflects the gap between Putin's definition of Ukraine as a vital national interest and the West's definition of Ukraine as an important but less vital interest....