The National Defense Strategy (NDS) for Donald Trump’s potential second term has omitted the term Extended Deterrence, which previously signified the U.S. commitment to protect South Korea from North Korean nuclear threats using its own nuclear capabilities. This change in the U.S. nuclear umbrella strategy for South Korea has raised security concerns as of Tuesday.
Defense analysts, however, argue that the absence of this specific terminology in the document does not necessarily indicate an immediate shift in the U.S. extended deterrence strategy. They point out that the nuclear umbrella remains a critical foundation for maintaining and strengthening alliances in the Indo-Pacific region.
Some experts suggest that by using less explicit language and implying conditional support based on U.S. interests and regional dynamics, the document allows for flexibility in adjusting the scope and intensity of security support to allies in the future.
The NDS, released by the U.S. on January 23, does not explicitly mention the protection of allied nations in its discussion of nuclear weapons operation and modernization beyond homeland defense.
While acknowledging the need for reliable nuclear operations in response to evolving nuclear threats, the document only commits to providing critical but more limited U.S. support for allied nations. The NDS, which expands on the National Security Strategy (NSS) released by the White House last December, serves as a key indicator of the practical direction of U.S. foreign and security policy.
This NDS marks a significant departure from the one issued during the Biden administration in 2022, which explicitly stated that nuclear modernization aims to deter threats against both the U.S. homeland and allies relying on extended deterrence.
The omission of extended deterrence in the NDS has sparked concern, particularly given the Trump administration’s apparent shift towards prioritizing the role of U.S. Forces Korea in countering China, potentially at the expense of Korean Peninsula security. Some interpret this as a sign of waning U.S. interest in preventing North Korea’s nuclear development and production.
U.S. Builds Allied Trust Through Nuclear Umbrella… Essential for China Containment Strategy
Despite these concerns, defense experts generally agree that the absence of explicit extended deterrence language in the NDS does not necessarily signal a dramatic shift in the U.S. commitment to its nuclear umbrella promise. They note that the Trump administration continues to emphasize the role of regional allies like South Korea and Japan in Indo-Pacific security, and U.S. officials maintain that the extended deterrence policy for these nations remains unchanged.
In fact, during recent Security Consultative Meeting (SCM) and Nuclear Consultative Group (NCG) sessions, the U.S. reaffirmed its commitment to enhancing extended deterrence and providing support using all U.S. military capabilities, including nuclear assets.
Professor Min Jeong-hoon from the Korea National Diplomatic Academy explains that the nuclear umbrella is a cornerstone of U.S. strategy for maintaining allied trust in the Indo-Pacific. While the U.S. is focusing on homeland and Western Hemisphere security, it’s also pushing for increased allied contributions to regional defense. Abandoning extended deterrence would contradict the U.S. strategy of countering China in the current geopolitical landscape.
Professor Min adds that the omission of extended deterrence in this NDS likely reflects a more cautious approach to allied cost-sharing, aligning with an America First agenda. It suggests that future extended deterrence may be more nuanced, with support levels adjusted based on U.S. interests and core strategic objectives, rather than the blanket commitments of the past.
Yang Uk, a researcher at the Asan Institute for Policy Studies, notes that extended deterrence fundamentally involves the U.S. providing nuclear deterrent capabilities against threats faced by allies. This concept clashes with the Make America Great Again (MAGA) ideology favored by Trump supporters. The inconsistent mention of extended deterrence across official documents may indicate that the level of U.S. deterrence support could vary based on South Korea’s performance as an ally.