Sanctions have so far been the most effective instrument of Western influence on Russia’s policy towards Ukraine, stopping the Kremlin from making a greater military incursion in the country. Restrictions were imposed against more than one hundred members of the Russian political and business elite, as well as dozens of Russian enterprises and banks. The annexation of Crimea and war in eastern Ukraine transformed assumptions about Russia, from a strategic partner, especially in energy, into a strategic challenge, mainly for regional security. Should Russia persist in challenging the principles of European cooperative order in Ukraine, by resuming fighting and taking over new towns and villages, the West will have to scale-up sanctions significantly. At the same time, the West should elaborate precise benchmarks against which to measure any potential Russian cooperative behaviour in Ukraine, before deciding to suspend or cancel sanctions.