AP Photo

NATO soldiers marching in Red Square on Victory Day. Moscow agreeing on a compromise resolution of the 40-year sea-boundary dispute with Norway. The sight of Prime Minister Vladimir Putin kneeling at the memorial to the Polish officers murdered by Stalin’s regime at Katyn. These are a few glimpses of what the New Europe newspaper two weeks ago described as a kinder, gentler Russia. But three questions immediately arise: Is this real? Why the change? And how to respond to Russia’s new foreign policy?

In this case, what you see is what you get. Russia’s tone, especially toward the United States, began to change last year, but the Kremlin’s support for a fourth version of United Nations Security Council sanctions on Iran demonstrates that, today,...