Beyond Policy Limits: Rethinking U.S.-Japan Command and Control

The Indeterminate Plan

U.S. Forces Japan (USFJ) is preparing for the biggest organizational change since its establishment. The planned reform, which was announced at the U.S.-Japan Defense and Foreign Ministerial Meeting (“2+2”) in 2024, is intended to reconstruct USFJ, which currently holds administrative authority over all U.S. forces stationed in Japan, as a joint operational headquarters reporting to the U.S. Indo-Pacific Command (INDOPACOM). This reconstructed USFJ would serve as a counterpart of Japan’s Joint Operations Command (JJOC) to be launched by the end of March 2025, which will command and control all the joint operations of the Japan Self-Defense Forces (JSDF).

These developments, on one hand, could be seen as a direct step toward deeper U.S.-Japan interoperability amid a deteriorating security environment. On the other hand, the sequence of the announcements—where the U.S. decision lagged behind Japan’s—raises the question:  why did the JJOC establishment precede that of the U.S, especially considering that the U.S. FY2023 National Defense Authorization Act mandated establishing a joint force headquarters in the Indo-Pacific without specifying its location or functions? Also, the 2024 “2+2” Joint Statement had a nuanced sentence that the renewed USFJ “is intended to serve as an important JJOC counterpart,” not as the primary JJOC counterpart, implying that the INDOPACOM will hold major authority over U.S. forces in Japan. While the joint statement says nothing about the concrete command and control (C2) relationships between the renewed USFJ and major U.S. service commands in Japan, it delegated the future development of the proposal to the bilateral working groups. Why was such a tentative reference to the reformed C2 arrangement made in the Joint Statement?

Possible Factors Contributing to the Problem

There are two possible interpretations about the tentative statement on this issue considering that the Joint Statement was announced in the summer of 2024. For one, Japan’s decision to possess the offensive strike capability—referred to as the “counterstrike capability” in Japan—propelled the United States’ willingness to closely coordinate with its Japanese counterparts. Given that the division of labor within the alliance is based on the premise that Japan focuses more on its role as a “shield” while the United States invests its resources on “the spear,” Japan’s shift away from its existing defensive capability-focused posture may require a reconfiguration of roles.

Specifically, it has been presumed that the United States would support Japan in the defense of the Japanese territory with offensive capabilities while Japan would support the United States with certain capabilities such as air defense, anti-submarine warfare (ASW), countermining, and logistics. Japan’s offensive strike capability would create a situation where both forces assume similar roles in the same offensive operations. Furthermore, this reconfiguration could cause concerns on the U.S. side if the Japanese side, however rare, were to be more inclined to strike enemy territories than the United States.

From the U.S. standpoint, even a limited Japanese-initiated strike could significantly affect escalation dynamics. From the Japanese perspective, however, Japan’s decision to strike enemy territories would be driven by how imminent the enemy attack may be—or worse, if its territory was already under attack—in which the will to limit the damage by their counterstrikes may outweigh the fear of further escalation.  Simply put, a perception gap toward escalation could arise between Japan and the United States due to the difference in geographical proximity despite their mutual agreement to defend Japanese territory from armed attacks. Therefore, the U.S. decision to move forward with elevating USFJ to the joint operational command can be interpreted as its attempt to recalibrate its influence over Japanese decisions under the banner of improving C2 coordination. 

Otherwise, it was Japan that pushed harder for the reorganization of USFJ. For Japan, enhancing C2 coordination is necessary for operating the offensive strike capability. C2 is closely related to situational awareness which is driven by intelligence, surveillance, and reconnaissance (ISR) capabilities. In operationalizing JSDF’s newly acquired capabilities, it would be harder to do so without the support from the U.S., including in the area of ISR and targeting at least in the near term. Thus, close C2 coordination between the United States and Japan is preferable for Tokyo even though there might be diverging interests between the two in some cases during contingencies. Having a U.S. counterpart to the JJOC commander stationed in Japan would help facilitate close coordination from the Japanese perspective. In this case, the United States could have taken Japan’s perspective into consideration and agreed in principle, while leaving the details somewhat open-ended.

Challenges to the Modernization of US-Japan C2 Cooperation

While it is premature to determine whether the U.S. desire to integrate Japan’s C2  into its own or Japan’s need for greater C2 coordination had a greater impact, political and diplomatic considerations likely drove the decision to reorganize USFJ. However, as previously stated, the proposal in the 2024 Joint Statement has little details, particularly in regards to the command relationships between the new joint operational USFJ and other U.S. service component commands not only in Japan—including the Navy’s 7th Fleet and the Marine’s Third Marine Expeditionary Force (III MEF)—but also with commands such as US Force in Korea (USFK). Without a clear C2 arrangement, this raises the question of whether the new USFJ commander should remain as a three-star commander, as he or she may experience difficulties in exercising the authority as the higher-operational command with the 7th Fleet and III MEF. Both of which have autonomous operational capacity, broader responsibility, and are led by a three-star commander. With no clear C2 arrangement between the two, it is possible that the INDOPACOM commander in Hawaii would override the command of USFJ in actual contingency. This would complicate bilateral coordination during contingencies. Organizational politics within the U.S. military may have contributed to the formation of this unclear architecture, but it may also be the result of the political factors mentioned above.

There is also a problem on the Japanese side. In the Japanese Diet, former Prime Minister Fumio Kishida already made it clear that the JSDF troops would never be subordinate to the U.S. commander. This was a premature declaration. Certainly, Japan may not necessarily be able to subordinate JSDF troops to the U.S. commander in all circumstances, due to the constraints of the Japanese Constitution, but strictly sticking to preserving the parallel C2 relationship would undermine effective bilateral operations where real-time coordination is required, including joint targeting and strikes. To mitigate the problem, it would be possible for Japan to have an intermediate solution by organizing these troops under the lower levels of the United States’ C2, such as tactical control (TACON) during the specific operations, and vice versa. 

Policy Recommendations

Review and clarify the C2 relationships between new USFJ and U.S. major service component commands not only in Japan but also in the theater of U.S. Indo-Pacific Command (INDOPACOM): U.S. individual service forces in Japan, especially the 7th Fleet and the III MEF, are stationed there not only for the defense of Japan, but also to respond to other regional contingencies including in the Taiwan Strait and the Korean Peninsula. Thus, the automatic subordination of those forces to USFJ may be difficult. An attempt for USFJ reform driven by political and diplomatic considerations might fail to fully take into account of increasingly complex joint operations among individual service forces that are acquiring more and more long-range-strike/multi-domain-operational capabilities. It might also fail to exploit the full potential of the Japanese capabilities through bilateral operations. Rather, the new USFJ can function as a de facto “forward-deployed INDOPACOM” element hosted in Japan with enhanced operational authority while keeping flexibility to cope with diverse regional contingencies. At least, the United States should conceptualize guiding principles on how the new USFJ controls major service forces in Japan alongside discussions with its Japanese counterpart.

Create templates of bilateral joint task forces for bilateral operations: The United States and Japan should create mission-specific bilateral joint task forces comprised of JSDF and U.S. forces, which are under TACON of either a Japanese or U.S. commander, for operations that are permitted under Article 9 of the Japanese Constitution. Both sides can prepare the templates of such forces to be filled with pre-designated units depending on the mission, including anti-submarine warfare, anti-surface warfare, air defense, and logistical operations. In order to facilitate mutual understanding of what the other side can do, both parties should also start wargaming on how such forces should be operated when joined by both uniformed and civilian offices.

Strict adherence to existing policy lines by both sides may not necessarily be beneficial. Japan and the United States should discuss a creative solution to meet diverse and sometimes conflicting requirements in a balanced manner.