More Russian troops piling in. Embassy staff pulling out. American forces on alert and sober diplomacy still on the docket. We examine Vladimir Putin's ways, means and motivations. The Omicron variant is making its mark in Mexico, a place that our correspondent says never really shut down. And considering the merits and the risks of work-related drinks. For full access to print, digital and audio editions of The Economist, subscribe here www.economist.com/intelligenceoffer