The end of the Cold War freed India-U.S. relations from the constraints of global bipolarity, but interactions continued for a decade to be affected by the burden of history, most notably the longstanding India-Pakistan rivalry and nuclear weapons proliferation in the region. Recent years, however, have witnessed a sea change in bilateral relations, with more positive interactions becoming the norm. India's swift offer of full support for U.S.-led counterterrorism operations after September 2001 was widely viewed as reflective of such change. The United States seeks to curtail the proliferation of nuclear weapons and ballistic missiles in South Asia. Continuing U.S. interest in South Asia focuses on ongoing tensions between India and Pakistan. U.S. concerns about human rights issues related to regional dissidence and separatism in several Indian states continue. Many U.S. business interests view India as a lucrative market and candidate for foreign investment.