The United States of America holds a significant position in the United Nations. The largest financial contributor, one of the founding members of UN, host of the UN headquarter, one of the Permanent-5 Members of the Security Council, and most importantly, the nation which advocated the foundational basis of UN's existence in the post-World War 2 era. Up to 2016, the US broadly supported the multilateralist approach of the UN at the global level carrying the domestic interests as well. However, with the election of Donald Trump as the President, there has been a paradigm shift in the foreign policy of the US, which is characterised by free trade, principled realism, emphasis on sovereignty, and reduced importance of international alliances. This approach and some other reasons have resulted in the disengagement of the USA from various UN entities through political and financial means.
Political Disengagement
In 2017, the USA had withdrawn from the United Nations Educational, Scientific and Cultural Organization stating the reason as past financial dues as well as an alleged “anti-Israel bias” of the organization. It was the second time the US had withdrawn from UNESCO, as earlier the then president Ronald Reagan had announced the withdrawal citing alleged corruption and “ideological tilt” towards the Soviet Union. Eventually, it rejoined the organisation in 2002 under the administration of George W. Bush. However, in 2011, the US under Barack Obama's administration cut off UNESCO's funding of over $80 million a year, accounting for 22% of the entire budget of the organization, as a result of the latter's acceptance of Palestine as a member, citing domestic legal limitations as the reason.
In 2018, a significant act of disengagement was taken by the USA by withdrawing itself from the UN Human Rights Council. The ostensible reason provided by the USA was concerning the alleged disproportionate focus being put on human rights violations specifically in Israel over other Members such as China, Cuba, and Venezuela by the council. This decision had made the US garner rational criticism by the international community mainly based on foreign relations of the US. Earlier, in 2006, at the time of inception of the council, George W. Bush had disallowed the US to join the council due to the presence of nations that were criticised by the US for human rights violations.
This year, Donald Trump moved to withdraw the US from the World Health Organisation with allegations of WHO being heavily influenced by China resulting in the catastrophic outbreak of COVID-19 pandemic. Before this, the US had halted the funding of WHO due to similar allegations. The withdrawal move would deprive the WHO of nearly $900 million biennially.
Such steps of withdrawal from UN entities display the perception of the US towards the UN. We see nationalist and sovereign sentiments, meant to serve domestic purpose, taking precedence over the international cause. For the US, engagement in international structures should lead to economic or political benefits. Since the new world order is seeing the growth and expansion of other states as significant powers striving for a healthy balance of power in the susceptible international sphere, the hegemonic ambition of the US certainly doesn't comply with these changing realities. Henceforth, unilateralism is the only means to practice for which it is essential to maintain the foreign policy outside the UN. These disengagements also allow other Members such as China and Russia, who are on the opposite side of the US, to have a greater role in the UN and enhance their influence at the global level.
Economic Disengagement
Being the largest economy in the world, the capability of the financial contribution of the US in the international sphere is massive. A quintessential example to define the capacity would be the contribution of the US of over $10 billion to the UN in 2018. However, on the contrary, the US has been lowering the funding to UN entities at a staggering rate since 2017 with future proposals of further lowering of funds already prepared. The US suspended all funding for the UN Population Fund starting in 2017; UNAIDS and the WHO also experienced significant cuts, losing about 30 percent and 20 percent of their funding by the US, respectively, in 2018. The US also halted contributions to the UNRWA in 2018. In future, Donald Trump proposes on decreasing the funds of UN Peacekeeping operations by nearly $500 million along with $500 million funding of US Contributions to International Organizations account, which includes assessed contributions to the United Nations and funds for specialized agencies, and abolishing an account for voluntary contributions to various UN programs in 2021 budget proposal.
Such lowering of funds is an example of diversion of funds the US is seeking to do, in future, in institutions that are essential for the US betterment. UN entities haven't been able to keep the US satisfied as per their plan of action, which has forced the US to divert their funds. The US also put its efforts in maintaining their foreign policy by being adamant on their stance regarding economic sanctions imposed on various countries. Bilateral economic relations prove to be more lucrative relatively over maintaining economic standards as per international organizations with other countries.
Other Disengagements
Besides the disengagement from the UN, the US has also withdrawn itself from the Paris agreement in 2019 citing “unfair economic burden” on American workers, businesses, and taxpayers but assuring to maintain the environmental standards. It had also withdrawn itself from the Joint Comprehensive Plan of Action in 2018 due to its “inefficiency” in nature. Donald Trump has also displayed his scepticism of the UN promoting multilateralism and being supportive of international and regional structures such as NATO and the EU.
Future
Despite concerns of administrative efficacy, philosophical and political criticism against the UN, Members tend to remain active in the organisation and put efforts to address such issues, rather than disengaging from it. As we have seen above, former US Presidents have also shown their disapproval by withdrawing from UN entities, but rather they were at rarer and extreme times and not as frequently as they are now.
The future course of this relation would be highly dependent upon the upcoming presidential elections in the US. A Democratic leader could seek to redefine this relation in a way contradictory to the means of the current President. With its acknowledgement, the nature of future relations could be broadly categorised into 3 paths, namely, a continuation on the same course, a complete withdrawal, or shift back to engagement.