Attacking Foreign Bases in Self-Defence

[Dorothea Anthony is a Senior Lecturer in the School of Law at the University of Wollongong, Australia.]

When the United States and Israel initiated military action against Iran in June 2025 and February 2026, one response from Iran was to target US foreign military bases. It struck these bases situated in the neighbouring United Arab Emirates, Qatar, Bahrain, Saudi Arabia, Kuwait, Jordan, and Iraq, and has continued doing so up to the time of writing, in reaction to US incursions. Within weeks of the 2026 war against Iran, the retaliatory strikes on the bases were estimated to have caused $800m in damage, leaving some “almost inoperable”. Western media outlets reported that Iran additionally launched ballistic missiles at the base in Diego Garcia in the Indian Ocean, although Iran said this operation, as well as strikes on Türkiye, Oman, and Azerbaijan, were “false flag” attacks by Israel.

The use of force by the United States and Israel against Iran was widely condemned in the international legal community in 2025 and 2026 as acts of aggression, for lack of evidence that Iran posed an imminent threat of committing an armed attack and because acting preventatively against anticipated threats has not gained currency in international law. On the other hand, prominent commentator Marko Milanovic maintained that it was not necessary and proportionate for Iran to respond by striking US military assets located in foreign nations. He argued that it was largely, albeit not entirely, the case that these bases were not used to attack Iran and that allied states were therefore justified in helping repel Iran’s counter-attack, which he specified as being directed at the foreign nations and not essentially the United States.

On this account, while international law permits self-defence, it accepts that where a state excessively relies on self-defence, to the extent of, for example, executing “attacks on countries in the Gulf”, those who initiated the aggression can be called on to restrain the defending state and summon other states to assist. In other words, the original aggressor can legitimately bring more nations into the conflict, on its side – in this case, a side that has caused untold devastation in Palestine, Lebanon, and Iran in the recent past, and in additional countries of the Middle East in recent decades. The offender is recast as the defender, with the narrative of good and evil turned on its head.

The difficulty with this reasoning is that while US bases are situated in other states, they are also an emanation of the United States, with a legal basis that ensures they can operate in an uncompromised way as part of an integrated network of US bases. Depending on the type of basing arrangement, an attack on a US overseas base may not simply be an attack on another nation but on the United States, with its unparalleled, coordinated global armour of about 750 bases located in around 80 states.

This post examines different forms of overseas military bases and different notions of sovereignty attached to them, and thus the question of who, in legal terms, is being attacked. It explains that base holders tend to assume sovereign rights or sovereignty, such that an attack on a foreign base may not exactly be characterised as an attack on another nation or permit its defence. However, foreign bases inevitably heighten the vulnerability of local populations, such that efforts to challenge them under international law should be renewed.

Targeting Bases in Claimed Territory

One type of overseas military base occupies territory that the base holder has claimed as its own. An example is the Sovereign Base Areas in Cyprus, one of which, at Akrotiri, was subjected to a “suspected drone attack” by Iran in March this year.

In 1960, as a non-negotiable condition for independence from the British coloniser, the Cypriot people agreed to relinquish these Areas, constituting 3% of the island. Until the international legal system rescinds this agreement for having been executed under duress or representing incomplete decolonisation, like in relation to the Chagos Archipelago, it is being upheld by the parties, despite protestations from successive Cypriot governments and the Cypriot people. That is, the Areas are deemed to be under full British sovereignty. Moreover, although 11,000 Cypriots still reside in them, the British government has insisted that they are used for military rather than colonial purposes.

Therefore, it cannot necessarily be said that the drone attack on the Royal Air Force at Akrotiri was an attack on Cyprus per se, but rather on the United Kingdom and its military apparatus. In addition, as the bases have long been used by the United States to support its wars in the Middle East, and could plausibly be used by this actor to launch strikes against Iran, the attack could be regarded as having been targeted more precisely at the US military.

In a recent statement by the UK government, which explained that it permitted the United States to use British bases in “collective self-defence of the region”, the United Kingdom only mentioned its disagreement with the Iranian attacks on commercial shipping and civilian infrastructure and the blocking of the Strait of Hormuz, as with UN Security Council Resolution 2817. Unlike Milanovic, it did not raise the Iranian attacks on foreign military bases as a justification for self-defence.

It would be unusual if the British government considered that the drone attack on the base constituted a violation of the sovereignty and territorial integrity of Cyprus, when its own military presence in Cyprus for 66 years following independence also has features of such a violation. If the safety of the Cypriot people were threatened by the drones, one could argue that it is largely because the British government placed these people in the path of war with its bases. The “de-escalation” that the statement calls for would appear to be achieved not by allowing the United States to use its bases, but, on the contrary, by removing the bases from the island altogether.

Targeting Bases in Foreign Territory

Another type of overseas base gives the base holder not sovereignty, but sovereign rights, under status of forces and defence cooperation agreements. Such agreements apply to most bases, including US bases in the Middle East, as well as Diego Garcia where the United Kingdom would be afforded “jurisdiction and control” and the “rights and authorities” of the newly recognised host nation, Mauritius, with exceptions, for 99 years upon ratification of the relevant treaty.

Different agreements provide for different levels of sovereign rights, but they can involve significant concessions by the host country, including “complete jurisdiction and control over and within said areas” that nevertheless remain under the “ultimate sovereignty” of the host nation, as in the case of the unwelcome US naval facility at Guantánamo Bay, which was historically meant to provide security to Cuba. Base holders can be a law unto themselves, with military personnel often enjoying jurisdictional immunity and even permitted to carry personal weapons on US bases. Accordingly, an attack on a foreign base may be an attack to varying degrees on the sending and receiving states. It is a simplification to say that the “territorial state” is the object of attack where such a state has largely conceded its territorial rights.

Whether the receiving state is facilitating the commission of an internationally wrongful act if war is illegally launched by the sending state is also a complex question. Receiving states that have willingly adopted a status of forces agreement have placed their territory at the disposal of another state and ceded a certain level of sovereignty. But, in broad terms, they have consented to the geopolitical ambitions of the sending state that may be achieved through interventionist military adventures, particularly in the case of the United States.

Receiving and sending states also place the population surrounding foreign bases at significant risk, both outside war, when hazardous training activities are conducted or military personnel commit crimes in the community, and during war, with the looming threat of retaliation. Mervin Magallona has thus written, in relation to US bases in the Philippines, “[w]hile American leaders claim that military bases are implanted in the Philippines for mutual protection and security, in the end it is mainland America which has all the protection from direct attacks and the Philippines all the risks of annihilation”.

It is logical that US and allied bases in close proximity to a warzone would be a target of retaliatory acts by states acting in self-defence, given the likelihood of the bases aiding US aggression in the area, such that the United States cannot be said to be an innocent bystander to its own actions. André de Hoogh reminds us that “logistical or other support” that would likely have been provided by the bases forms part of the definition of an armed attack outlined in the Nicaragua case by the International Court of Justice. Ori Goldberg adds that nations hosting the bases have contributed not just their soil but their airspace to the conflict. Kostas Kalevras also questions what proportionate self-defence by Iran should be when the United States and Israel have threatened Iran’s very existence. The US bases surrounding Iran from various directions heighten this threat and the prospect of retaliation from Iran, and therefore play a key role in undermining safety in the region.

Targeting Joint and Allied Bases

Yet another form of overseas base is one that multiple states hold in concert with one another. An example is the base at Diego Garcia, with the agreement between the United Kingdom and Mauritius and the agreement between the United Kingdom and the United States authorising the latter two states to operate the base jointly. Considered one of the more strategically important military outposts in the United States’ constellation of bases, the base has been used by the superpower since the 1970s and built with Iran in mind, as with the “necklace” of Middle Eastern military installations with tens of thousands of US troops.

A further example is Pine Gap in Australia, which is known as one of the world’s largest spy bases. Even though, in practice, the US government has effective control over its operations, with the Australian government famously unaware of the way it has been used by the long-time ally, and in any case generally uncritical, the base is officially jointly operated by Australia and the United States. Hence, with its surveillance system conceivably gathering intelligence on Iran to help direct US and Israeli strikes and detect threats, reportedly more actively following the damage to US bases in the Persian Gulf, the joint nature of the base raises questions about the complicity of the Australian government in the atrocities, just as the United Kingdom has been identified as a “co-belligerent” regarding Diego Garcia. Furthermore, any such complicity could technically make the base a potential target of Iranian counter-attacks in self-defence.

Warfare from bases jointly held with the United States and a host nation draws the host into US conflicts more readily. Moreover, bases with intercontinental intelligence capacity, such as Pine Gap, and bases situated near a conflict zone are particularly vulnerable, as are the communities surrounding these bases. Indeed, there has long been an active protest movement at the perimeter of Pine Gap, which recognises the high level of risk that the base poses and includes Aboriginal people who maintain that they never ceded the sacred area to the Australian government, let alone to the United States.

Conclusion

Whether sovereignty or sovereign rights attach to a particular overseas base, and whether the host nation willingly cooperates in the operation of the base, can influence the level of independence of the host country from a conflict initiated by the base holder. Less independence means that when the base is counter-attacked, actions in purported self-defence of the host nation can present as a deliberate escalation of war rather than a genuine form of defence. Moreover, with overseas bases that exist without the consent of the occupied nation, it is not plausible that the occupying power has a real interest in defending the host country, as opposed to its own interests.

The case of Iran provides a useful example of how the positioning of foreign bases of the aggressor as a neutral victim in war can serve to build momentum for the aggression. At the same time, the bases provide a launchpad for any further use of force and can thereby help draw more people more deeply into the conflict.

Although foreign bases are not the ultimate cause of war, they assist its progression. Therefore, rather than remain silent on foreign bases, save for some debates at the UN General Assembly in the 1960s, the international law regime should question their role in contributing to the renewed wave of US and Israeli interventionism and war. It ought to identify the evidence that they decrease rather than increase people’s security in times of conflict, especially in resource-rich and strategic regions. Ultimately, it should represent the will and needs of the people in host nations, who overwhelmingly favour their dismantlement in an increasingly volatile world.