Firing a SLBM at the Northeast in Modern Warfare 2. It did do what it was meant to from Price's perspective but the US government currently fighting a full-scale Russian invasion had no way of knowing that it was just a single EMP shot, and even if it was that would have been seen as a tremendous danger posed by the Russians and would have at the least incurred a counter launch to shut down everything from Kaliningrad to Petropavlovsk, and quite plausibly actual nuclear strikes.