In Call of Duty: Modern Warfare 2, the action will take place all around the globe, from Afghanistan to Brazil, the Caucasus to the USA. It's up to Task Force 141 and Gary 'Roach' Sanderson, one of the five characters you can become, to stop this group and put an end to the conflict.
The storyline of Call of Duty: Modern Warfare 2 starts in Russia, where you'll encounter a thriving ultra-nationalist group led by the bloodthirsty terrorist Makarov.