Unlike the Cold War, when the national strategies of the United States and Soviet Union shaped the course of world development, changes in the international political ecology in the first two decades of the 21st century are mainly the result of a changing international strategy by the U.S., as the world has remained unipolar in its global system and balance of power since the disintegration of the former USSR. Meanwhile, over the past 20 years China has gained substantial political and economic influence.
The first strategic change in the international political ecology in the 21st century followed the Sept. 11 incident in 2001 and the rise of non-traditional security threats as a global challenge. The attacks on New York and Washington were a shocking illustration of a non-traditional security threat that was no longer merely an occasional local crisis with some influence on security and order in the international community. Traditional and non-traditional security threats have become the two primary challenges confronting the world community in the 21st century.Correspondingly, America's global strategy had to evolve to deal with both the erosion of the unipolar system brought by competition between great powers and the challenge of terrorism, which had already impacted heavily on the U.S.-led international order and even threatened its homeland security. In the first few years after 9/11, the U.S. was compelled to develop anti-terror partnerships with Russia and China, leading to a relaxation of competition in the early years of the 21st century, thus providing a brief strategic period of opportunity for Russia and China to focus on development at home.In the current situation, however, competition between the big powers is a top priority in the national strategy of the U.S. for the near and medium term, and the possibility of returning to major-power cooperation based on a sense of urgency to handle non-traditional security threats is minimal.
Second, the new empire syndrome became apparent during the financial crisis. Since then, American administrations have been readjusting the country's external strategies over and again, with a slackening of the previously solid unipolar system. The two anti-terror wars after 9/11 in Afghanistan (the actual one) and Iraq (the nominal one) cost the U.S. $3 trillion in direct military expenditures, devouring virtually all of its Cold War victory dividends. After the $100 and $200 billion fiscal surpluses in fiscal years 1999 and 2000 under Bill Clinton, the George W. Bush administration experienced rapid increases in both fiscal deficits and government debt. The international strategy choices made by the American government to safeguard the liberal international order and deal with the challenges of terrorism have not only caused extensive international disputes but have also overdrawn America's national strength. The two wars diverted U.S. attention from its own development — for example, the hidden industrial hollowing-out, as revealed by the economic declines in three consecutive quarters in 2001. They also consumed the government's financial capacity to defuse a major crisis, which became apparent in 2008. The strategic contractions by the Obama administration in his two terms steered the stable unipolar system born after the Soviet disintegration into transition toward a slack unipolar system.
Further, in the 10-plus years since the financial crisis, the unilateralist and isolationist tendencies of the U.S. have gradually increased. The liberal ecology of international politics and economics was seriously undermined by its very founder and presumed guardian.The Obama administration followed a “smart power” diplomatic philosophy and pursued a strategic contraction globally, featuring local implementation of isolationism, but it did not abandon the liberal values and international rules in general. For example, it made great efforts to advance the TPP and TTIP.Since Donald Trump came to office, however, in a reality where its system of alliances is much needed, the U.S. has extensively applied a unilateral logic to its actions to the extent of antiglobalization. On one hand, the Trump administration has withdrawn from various multilateral international agreements and treaties. On the other, it has taken “America first” unilateral actions to change existing cooperation mechanisms with its allies, partners and competitors. Both have seriously undermined the liberal international system, which has been based on open consultation and held together by universally observed norms.
Additionally, with the change of its primary designated competitor, the U.S. has started to give up its old efforts to develop mechanisms for strategic stability, which leads to the anarchy of arms races and nuclear proliferation. With China locked in as its primary strategic rival, the U.S. has not only withdrawn from the INF treaty but also adopted an indifferent attitude toward the New START Treaty, which is about to expire. Its policies also raise a suspicions that the country is merely using the DPRK nuclear issue to pin down China.