The last time Ukraine signed a peace accord with Russia, 10 years ago, it brought only sporadic violence, mounting distrust, and eventually full-scale war. Here’s what we can learn from that history.

More than three years into Russia’s invasion of Ukraine, Russian President Vladimir Putin has maintained inflexible, maximalist conditions for any potential agreement that would end the war. Putin said Thursday he supports in principle the idea of a 30-day ceasefire — proposed by the United States and to which Ukraine has agreed — but noted that its implementation raises many questions,