On May 7, the Associated Press published an unconfirmed report indicating that the Trump Administration is considering adopting the term “Arabian Gulf” in place of the historically established name “Persian Gulf.” During a press briefing, President Trump remained deliberately noncommittal, stating, “I don’t want to hurt any feelings,” and added that he would make a final determination during his upcoming visit to the Middle East. As of this writing, no official change has been enacted, but speculation is mounting that the administration may soon formalize the use of “Arabian Gulf” in official U.S. communications. This would mark the second instance of the Trump Administration attempting to revise a long-standing geographic name, following the recent executive order renaming the Gulf of Mexico as the “Gulf of America.”
The dispute over the naming of the body of water between Iran and the Arabian Peninsula has long been a point of diplomatic tension between Iran and several Arab states. However, the recent wave of unilateral naming decisions — and the administration’s apparent willingness to adopt revisionist terminology — raises critical questions about what international law actually says about geographic naming disputes. This post examines the relevant legal frameworks and explores how these apply to the ongoing controversy over the name of the Persian Gulf.
Background
The dispute over the name of the Persian Gulf is not primarily a territorial disagreement but rather a contest over cultural identity, historical narrative, and political legitimacy. The name “Persian Gulf” has been in consistent use for over two thousand years, appearing in ancient Greek, Roman, Islamic, and later European maps and texts (here, here and, here). Classical geographers such as Ptolemy, Strabo, and Pliny the Elder referred to the waterway as Sinus Persicus. This usage was sustained by prominent Islamic scholars throughout the medieval period and remained the dominant terminology in global cartography well into the modern era.
The contemporary dispute traces its origins to the late 1950s, notably with the publication of British diplomat Roderic Owen’s 1957 book The Golden Bubble, in which he referred to the waterway as the “Arabian Gulf.” This departure from established nomenclature coincided with the rise of Pan-Arab nationalism, particularly under the leadership of Egypt’s Gamal Abdel Nasser. By the 1960s, several Arab governments began incorporating the term “Arabian Gulf” into their official discourse, framing the renaming as a reflection of regional solidarity and identity.
Iran has consistently and formally objected to this shift. Meanwhile, Arab states advocating for the alternative designation often invoke anthropological and geopolitical arguments (here) with emphasis on the greater number of Arab populations residing along its shores along the longer Arab coastline —as grounds for revising the name. For Iran, however, the issue remains a matter of historical continuity and persistent international recognition.
International Law and Naming Disputes
Name disputes are not new in international law. In addition to the long-standing dispute over the use of “Persian Gulf” versus “Arabian Gulf,” similar controversies have caused diplomatic frictions in cases such as “Sea of Japan” versus “East Sea” (between Japan and South Korea) (here), and in competing uses of names like “Zaire” and the “Democratic Republic of Congo” (raising issues of recognition between Congo-Brazzaville and Congo-Kinshasa) (here). Unilateral name changes by states have also led to procedural complexities and delays in recognition within international institutions.
However, the first name dispute formally adjudicated by the International Court of Justice (ICJ) was the case of Former Yugoslav Republic of Macedonia v. Greece (2011). At issue was Greece’s objection to the use of the name “Republic of Macedonia,” which it viewed as implying a territorial claim over the Greek region of Macedonia and appropriating Hellenic cultural heritage (para. 16). In 1995, the two states signed an Interim Accord under which Greece agreed not to object to Macedonia’s membership in international organizations as long as it used the provisional name “the former Yugoslav Republic of Macedonia” (FYROM) (paras. 20-21). Despite this, in 2008, Greece opposed Macedonia’s bid to join NATO, arguing that the name dispute remained unresolved (para. 75).
Macedonia subsequently brought the case before the International Court of Justice (ICJ), alleging that Greece had violated the terms of the Interim Accord (para. 12). In its 2011 judgment, the ICJ ruled in Macedonia’s favor, finding that Greece had breached its obligation not to object to Macedonia’s admission to international organizations (para. 168). However, the Court deliberately refrained from addressing the broader issue of the name dispute, citing United Nations Security Council Resolution 817, which recommended resolving the issue “in the interest of the maintenance of peaceful and good-neighbourly relations in the region.”
Critical Date Theory
Naming disputes and historic rights are categorically distinct under international law—the former concerning symbolic, cultural, and geopolitical designations, and the latter referring to legal entitlements over maritime spaces—certain criteria developed in the context of historic rights may be relevant in naming controversies as well. Historic rights typically rest on the long-standing and continuous exercise of a right, coupled with public acknowledgment and acquiescence by other states. Although naming disputes do not directly confer sovereignty or resource rights, these evidentiary factors — such as persistent usage and lack of formal objection — can help evaluate the legitimacy of competing claims (here, p.185). In the case of the Gulf of Mexico, it has been suggested that altering the name could gradually erode preexisting regimes of access and maritime entitlements, even potentially influencing questions of sovereignty (p. 61). In the case of the Persian Gulf, although the effects may be more indirect, a prolonged and systematic effort to undermine the established naming convention could, over time, affect maritime boundary claims and potentially escalate tensions among the coastal states.
Although name disputes are not formally categorized under historical title claims in international law, they often rely on threads of historical continuity to assert naming rights and the associated priority of usage. The notion of ‘priority rights’ linked to a particular geographical name is recognized both in the maxim prior in tempore, potior in iure, and also in the framework of geographical indications within intellectual property law (here). In the context of the Persian Gulf, it has been suggested that the ‘critical date’ theory effectively captures both dimensions—long-standing usage and legal recognition—thus serving as a useful analytical tool in addressing naming disputes. In one of the rare analyses of the Persian Gulf naming controversy, Ali Omidi argues that “critical date theory” could provide a more objective standard for determining such disputes. According to Omidi:
“‘[The] critical date’ establishes a specific point in time after which the facts of a dispute become fixed and cannot be altered by the actions of the involved parties. This means that any events, actions, or circumstances that occur after the critical date are not deemed relevant to the dispute, and they cannot be used to justify or support a party’s claims or defenses” (p. 4).
‘Critical date theory’ has been used primarily in territorial disputes as a criterion for assessing claims against temporal factors. As early as 1963, Goldie suggested that the doctrine had the potential to extend to “many types of disputes in which the operative facts emerge over a continuing period of time” (p. 1252). Drawing on a well-supported position taken by Sir Gerald Fitzmaurice in the classic Minquiers and Ecrehos case (France/United Kingdom), Goldie posits that:
“The critical date can only be determined after the parties have taken up their final positions in terms of international law and [stand] on their respective rights” (p. 1254).
This is the point at which the parties’ positions in a dispute become solidified, and it becomes clear that overlapping claims are in direct conflict. At first glance, ‘critical date theory’ appears to have only procedural relevance, especially in determining jurisdiction. However, some jurists, such as Fitzmaurice, have argued that it can also influence the substantive dimension of a dispute:
“Whatever was the position at the date determined to be the critical date, such is still the position now. Whatever were the rights of the parties then, those are still the rights of the parties now. If one of them then had sovereignty, it has it now, or it is deemed to have it” (p. 64).
The critical date criterion has been invoked in a variety of cases most notably by the Permanent Court of Arbitration in Netherlands v. United States (1925), and the ICJ in Indonesia v. Malaysia (2002), and Cameroon v. Nigeria (2002).
Omidi argues that the critical date doctrine is applicable to the Persian Gulf naming dispute and identifies the late 1950s and early 1960s as the period in which the dispute crystallized into a serious disagreement. While it is true that the primary application of critical date theory has been to determine historical title over territory, there is no compelling reason to exclude name disputes from its purview (p. 1). The doctrine may offer a useful framework for resolving such disputes, especially given that international law does not provide specific rules governing naming contests among states. Critical date theory also facilitates an appeal to historical authenticity rather than to more arbitrary factors, such as power dynamics or the demographic composition of coastal populations. This aligns with the principle prior in tempore potior in jure, which grants naming rights to the “first-in-time” user. Furthermore, critical date theory implies that states do not possess exclusive sovereign rights to name maritime spaces that signify shared areas, particularly when such names can influence territorial title and cultural heritage. As one commentator has observed:
“Domestic laws are no less purely domestic acts than are declarations made by government entities… To the extent that such documents or actions… do in fact produce legal effects in the international sphere, such instruments are international in nature” (p. 569).
This position is reinforced by the analogy between historical names and geographical indications, as protected under trademark law, which asserts that states have a unilateral legal entitlement to adopt names and symbols — provided they do not conflict with existing entitlements (here, pp.577-578).
Applying critical date theory to the term “Persian Gulf” favors Iran’s claim, given the depth and continuity of historical usage. Current state practice and customary international law also contribute to the consolidation of naming rights, making the issue a complex intersection of historical title, state conduct, and legal interpretation.
Persian Gulf in International Usage
Global usage continues to reflect a longstanding consensus on the name “Persian Gulf,” grounded in both history and international practice (here and here). As one influential working paper on geographical nomenclature noted:
“if we were to presume that the sea did not have a name during history, and … geographers and specialists were to select a name for this gulf, doubtlessly, they would find no better name than Persian Gulf because Iran [Persia] is the largest country adjacent to this water body” (p. 1).
This view has informed consistent directives from international organizations. For instance, the United Nations Secretariat has, on multiple occasions, instructed its personnel to use only “Persian Gulf” in official documents and communications.
The matter has also attracted attention from major media outlets, cartographic authorities, and digital platforms. The Associated Press Stylebook describes the Persian Gulf as the “long-established name for the body of water off the southern coast of Iran,” adding that “Arabian Gulf” should be used only in direct quotations and clarified as the less common usage. Similarly, National Geographic, after briefly listing “Arabian Gulf” parenthetically in 2004, reversed that editorial decision following public outcry and re-affirmed that the “internationally accepted name is Persian Gulf.” The June 2010 National Geographic Style Manual reiterated that “if Arabian Gulf is used in text, it should be explained,” while cartographic labels must retain “Persian Gulf” as the primary designation.
From an American perspective, “Persian Gulf” has been the official label for U.S. government use since a decision by the State Department’s Board on Geographical Names in 1917 (see also here). The U.S. National Geospatial-Intelligence Agency’s GEOnet Names Server continues to list “Persian Gulf” as the only conventional name, while cataloguing 14 alternative variants such as “Arabian Gulf,” “Gulf of Iran,” and “Gulf of Fars.” Nevertheless, in recent years, certain branches of the U.S. military have issued instructions to personnel stationed in Arab Gulf states to adopt the term “Arabian Gulf” in order to comply with local sensitivities and legal requirements (here, p. 59). Similar adjustments have been made by American universities operating in the region, some of which have omitted references to “Persian Gulf” in teaching materials.
Trump’s potential recognition of the term “Arabian Gulf” represents a late entry into a broader, gradual shift within the United States toward adopting that terminology. Yet, such unilateral recognition — even if echoed by other states — cannot override the established historical name. As legal doctrine makes clear, even within the framework of customary international law, claims based on historical title are treated as a distinct category in which “priority rights” are determined by historical usage rather than by unilateral declarations or subsequent recognition by other states (see also here).
Conclusion
The dispute over the naming of the Persian Gulf is far from a mere semantic quarrel; it serves as a proxy for broader debates surrounding historical legitimacy, regional identity, and the interpretation of international legal norms. While international law lacks a comprehensive framework governing naming rights, principles drawn from trademark law and the doctrine of historical title under the law of the sea can help structure the legal reasoning in such cases. In this regard, the ‘critical date theory’ offers a conceptual bridge between naming rights and historical title, anchoring disputes in both temporal continuity and legal precedent. Efforts to rename historically recognized geographical spaces — especially those with shared regional significance — may offer short-term political capital for certain leaders or align with specific ideological agendas. However, states are not granted carte blanche to unilaterally revise names that carry longstanding historical usage and international recognition.