“Another such victory and we shall be utterly ruined,” the Greek King Pyrrhus of Epirus supposedly muttered after his army lost thousands of soldiers while defeating the Romans at Asculum in 279 B.C. Similar words might well apply to Russia’s conquest of Mariupol, Ukraine, which the forces of Russian President Vladimir Putin completed Monday. The city’s last few hundred Ukrainian defenders, holed up inside the vast Azovstal steel plant on the outskirts of town, have surrendered and been taken to Russian-held areas of Ukraine. Russia thus achieved a strategic objective: to control an uninterrupted swath of territory along Ukraine’s southeastern edge, including Crimea and most of its Black Sea coast.