The recent focus on Trump’s “America First” foreign policy in South Korea has been extremely narrow, often concentrating on specific issues such as the withdrawal of U.S. troops from South Korea, the possibility of U.S. support for South Korea’s nuclear armament, or tariff increases. However, there has been little analysis in South Korea of the context for why the “America First” foreign policy has taken root within the Republican Party. Without this understanding, there is a risk that South Korea’s policy toward the United States may be formulated too narrowly.

The differing foreign policy outlooks of the leading candidates for the Republican Party’s 2024 presidential nomination between “America First” candidates such as Ron DeSantis and Vivek Ramaswamy and establishment Republicans such as Chris Christie and Nikki Haley suggests that intra-party tensions are unlikely to disappear anytime soon. However, if former President Trump is re-elected, many of the American First policies that were partially blocked during his first term are likely to be revived and a second Trump term is likely to pursue a foreign policy based on geo-economics, restraint and reciprocity.

In this context, this Issue Brief examines the various discussions surrounding foreign policy within the U.S. Republican Party, particularly the “America First” foreign policy, and analyzes the implications of these changes for the security landscape in Northeast Asia, including South Korea. Specifically, it explores three representative types of foreign policy strategies under the rhetoric of “America First”: “restraint,” “prioritization,” and “maintaining U.S. dominance.” It emphasizes that former President Trump is likely to selectively use the policies proposed by these strategies. These strategies are not necessarily ideologically driven but are part of a process of systematization at the policy level. Given the recent trend of ideological conservatism among Republican supporters, it seems likely that restraint in foreign policy may be more frequently pursued in the future.

In fact, within the Republican Party, conservative realism and conservative internationalism have coexisted as foreign policy orientations. Notably, conservative realism emphasizes a small government orientation and nationalist tendencies. These align with the “geopolitical restraint based on scarcity” and “economic nationalism” amplified through populism by the Trump camp. This “America First” orientation poses a challenge to the current ROK-U.S. relationship, which is based on the liberal international order. To manage this challenge, it is necessary to understand the diverse landscape within “America First” and maintain the resilience of the East Asian security architecture through proactive consultations not only with the United States but also with regional allies.

 

1. Diverse Types of U.S. “America First” Foreign Policy

 
Among many other reports, “The True Meaning of Trump’s MAGA,” published by Peter Navarro, the former Director of the Office of Trade and Manufacturing Policy, served as a basis for “Agenda 47,” the official 2024 Republican Party Platform. In his report, Peter Navarro makes several arguments: First, expanding tariffs on China to strengthen the U.S. manufacturing base; second, building borders and increasing border protection to prevent illegal immigrants from countries such as Guatemala, Honduras, and El Salvador; and lastly, he calls for ending U.S. “endless wars,” particularly in the Middle East. This stance is reiterated in “Agenda 47,” which includes policies such as eliminating welfare benefits for illegal immigrants, reducing energy dependence on the Middle East, expanding U.S. military power, establishing missile defense systems, increasing contributions from NATO allies, establishing fair trade practices through the “Reciprocal Tariff Act,” ending the war in Ukraine, and reducing the budget for climate change.

Both reports highlight a shift in U.S. foreign policy influenced by a populist approach within the Republican Party. Traditionally supportive of free trade, the party is now embracing “America First” policies, including tariffs, export controls, and anti-globalization. While initially targeting China, these policies have global repercussions.

The “America First” foreign policy can be categorized into three types as shown in Table 1. These types are not theoretically established but rather reflect the interests of various factions within the Republican Party. This indicates a lack of consensus on Trump’s “America First” approach within the party. During his presidency, Trump pursued diverse foreign policies within these types. The future direction remains uncertain, with some Republicans suggesting a possible compromise between Trump’s and Reagan’s principles. However, Trump’s reluctance to adhere strictly to any specific ideology adds to the uncertainty.

 

Table 1. Various Interpretations and Claims Regarding “America First” within the Republican Party

Source: Based and reconstructed from Majda Ruge, Jeremy Shapiro, “Polarized Power. The Three Republican Tribes that could define America’s relationship with the World” European Council on Foreign Relations (November 17, 2022)

 

It is important to note that the relevant figures mentioned for each type in Table 1 do not all share the same perspective, nor have they formed concrete factions among themselves. In short, if former President Trump is re-elected, he will likely approach matters pragmatically within the three categories in Table 1, depending on the issue and context.

Trump’s approach is characterized by a focus on Great Power competition, especially with China. While the United States is unlikely to abruptly withdraw its forces from the region, there will certainly be an increased emphasis on security burden-sharing for regional allies, who are expected to make efforts to maintain the balance of power within their respective regions. He also rejects international institutions that limit U.S. autonomy and favors a geo-economic perspective over military intervention. Accordingly, there are predictions that the Biden administration’s efforts to revitalize regional minilateral cooperation might weaken. However, if the importance of minilateral consultative bodies such as the AP-4 (Asia Pacific 4), the Quad, ROK-U.S.-Japan cooperation, and U.S.-Japan-Philippines cooperation is emphasized, not from the perspective of regional ‘security order architecture’ but rather in terms of offshore balancing and the resilience of the U.S. defense industry, they could still be maintained. In the Middle East, Trump emphasizes reducing the U.S. role while supporting Israel. The Republican Party is expected to experience increased divisions over the Ukraine war, with Trump likely favoring a cautious approach. Overall, Trump’s foreign policy leans towards populism, prioritizing domestic concerns, regional power balances, and a reduced role in the global liberal order.

 

2. Background of the Emergence of America’s “America First” Foreign Policy

 
The Republican Party’s foreign policy approach can be divided into two categories: Conservative Internationalism and Conservative Realism. Since Dwight Eisenhower’s victory over isolationist Robert Taft in the 1952 primary, the Republican Party has largely embraced Conservative Internationalism, which promotes expanding U.S. military and economic power, supporting global democracy, and maintaining alliances and a military presence abroad to sustain U.S. global influence. In contrast, Conservative Realism advocates limiting U.S. foreign interventions and prioritizing domestic concerns such as sovereignty, territorial borders, and homeland security. The Trump camp often cites the Reagan administration as the inspiration behind the “America First” policy and the “Make America Great Again (MAGA)” slogan. They argue that Trump’s platform echoes Reagan’s “peace through strength” philosophy. However, there are three key distinctions between the two.

The first distinction is the economic approach. At the 1980 Republican National Convention, President Reagan gave a speech in which he said, “Thanks to the economic policies of the Democratic Party, millions of Americans find themselves out of work. Millions more have never even had a fair chance to learn new skills […] it is time to put Americans back to work; a party ready to build a new consensus with all those across the land who share a community of values embodied in these words: family, work, neighborhood, peace and freedom.” The Trump camp claims that this speech reflects the core values of MAGA. President Reagan’s message was indeed aimed at the American working class. However, in contrast to Reagan’s message, the Trump camp criticized the negative impact of globalization, particularly the economic harm it caused to American workers. Trump emphasized “fair” trade practices, arguing that American workers were being unfairly disadvantaged by foreign competition, especially from Asia and Latin America.

The second distinction is government size and populism: Reagan and Trump both supported the idea of small government, but their approaches differed in motivation and application. Reagan’s stance was rooted in traditional Republican opposition to expansive federal programs such as the New Deal. Trump, however, used a small government philosophy as a cornerstone of his populist “America First” agenda, appealing to voter resentment toward government overreach and focusing on reducing federal intervention, especially in areas like healthcare and immigration.

The third distinction is its stance on internationalism. A skeptical attitude toward internationalism has also emerged due to factors such as the decline of U.S. manufacturing due to China’s participation in the World Trade Organization and the fatigue from over 20 years of wars in Afghanistan and Iraq. Regarding the decline of manufacturing in the United States, discontent within the Republican Party had already been present to such an extent that, in 1996, Republican political advisor Patrick Buchanan proposed a trade policy based on reciprocity and a reform of immigration policies. Additionally, as the wars in the Middle East extended beyond responses to the 9/11 terrorist attacks and evolved into efforts to rebuild democratic nations, American voter dissatisfaction increased. In response to this, Trump declared at the Republican National Convention that “America First, not globalism, will be our credo.”

In summary, the “America First” policy or MAGA (Make America Great Again) promoted by former President Trump, can be seen as a policy direction rooted in populism and nationalism, capitalizing on domestic shortcomings. This differs in its background and logic from the principles of the Reagan administration. However, as discussed earlier, the “America First” foreign policy still exists in various forms, and how this orientation will converge or be concretely realized in policy terms will depend on who fills the key positions in the White House and major government departments if former President Trump is re-elected.

 

3. The Impact on U.S. Foreign Policy

 
The “America First” foreign policy of the Republican Party in the United States has moved beyond just the rhetoric of former President Trump and is gaining support from voters. Populist and economic nationalist strategies, which leverage voters’ economic hardships, will continue to be utilized by Trump’s camp. Consequently, if former President Trump is re-elected, the priorities of U.S. foreign policy are likely to focus on economic issues and immigration. In this context, there is also a greater possibility that a more restrained approach to foreign policy, excluding competition with China, might be more frequently proposed.

Understanding the populist and economic nationalist strategies that underpin Trump’s policies is essential for countries such as South Korea, which must navigate complex security, economic, and technological relations with the United States. The current U.S.-China strategic competition is not merely a bilateral rivalry between the two great powers, but rather a competition between coalition hegemonies, in which each country justifies its international order and competes with coalitions of like-minded countries. In this context, a shift in U.S. foreign policy direction could not only affect ROK-U.S. relations but also alter the direction of alliance policies and the maintenance of the international order, ultimately weakening the durability of coalition hegemony.

The Yoon Suk-yeol administration in South Korea has shifted its approach from strategic ambiguity to strategic clarity, aligning more closely with U.S.-led security initiatives in the Indo-Pacific region. This strategy seeks to enhance cooperation among like-minded countries and contribute more actively to regional security, particularly in countering China’s influence. However, a Trump re-election could challenge the current international order with an emphasis on bilateral, transactional diplomacy, and increased security burden-sharing among U.S. allies. In this context, South Korea will need to engage proactively not only with the U.S. but also with regional partners such as Japan, Australia, and Vietnam to strengthen cooperation across security, economic, and technological domains.