THE NAME of the weapon, designed in the late 1980s, was both an acronym—Army Tactical Missile System (ATACMS)—and, when said aloud, an exhortation—“attack ’ems”. But Ukraine could not, in fact, attack ’em—at least not inside Russia, not until November 17th, when American news outlets reported that Joe Biden, America’s president, had changed course and given Ukraine permission to use the advanced long-range missiles on Russian soil. The decision will not dramatically change Ukraine’s flagging fortunes on the front lines, though it will boost morale and strengthen the country’s hand ahead of negotiations pursued by Donald Trump after January 20th. A tumultuous two months lies ahead first.