Vladimir Putin seized Crimea from Ukraine, a bold land grab that set the stage for Russia to invade its neighbor in 2022. The quick and bloodless seizure of the diamond-shaped peninsula, home to Russia's Black Sea fleet and a popular vacation site, touched off a wave of patriotism and sent Putin's popularity soaring. «Crimea is ours!» became a popular slogan in Russia.
Now that Putin has been anointed to another six-year term as president, he is determined to extend his gains in Ukraine amid Russia's battlefield successes and waning Western support for Kyiv.
Putin has been vague about his goals in Ukraine as the fighting grinds into a third year at the expense of many lives on both sides, but some of his top lieutenants still talk of capturing Kyiv and cutting Ukraine's access to the Black Sea.
The largest conflict in Europe since World War II has sent tensions between Moscow and the West soaring to levels rarely seen during even the chilliest moments of the Cold War.
When he seized Crimea in 2014, Putin said he persuaded Western leaders to back down by reminding them of Moscow's nuclear capabilities. It's a warning he has issued often, notably after the start of his full-scale invasion; in last month's state-of-the-nation address, when he declared the West risks nuclear war if it deepens its involvement in Ukraine; and again on Wednesday, when he said he would use that arsenal if Russia's sovereignty is threatened.
Analyst Tatiana Stanovaya says Putin