While the ceasefire process between the United States of America (USA) and the Islamic Republic of Iran continues, uncertainty remains over whether a new round of negotiations will be held in Pakistan. In anticipation of the possibility that no peace agreement will be reached, both sides have undertaken certain military preparations and planning. In particular, Iran’s so-called “pre-emptive” moves prior to entering the diplomatic table have drawn attention. For instance, when delegations arrived in Pakistan for the first round of talks, it was reported in the media that the Iranian side refrained from immediately proceeding to direct negotiations and instead put forward a number of preconditions. These reportedly included demands such as a ceasefire in Lebanon, the unfreezing of Iranian assets, and the exclusion of the nuclear issue from the scope of negotiations.
In response, the Trump administration concluded that Iran was attempting to secure certain advantages before entering the negotiation process. Consequently, the United States adopted a reciprocal “pre-emptive” approach and began imposing a naval blockade on Iran prior to the second round of talks. Following the ceasefire in Lebanon, Iran announced the reopening of the Strait of Hormuz; however, President Donald Trump declared that the blockade against Iran would continue. In this context, the United States has maintained coercive measures such as the blockade in an effort to compel Iran toward peace. Iran, in response to the ongoing American blockade, announced that it had closed the Strait and, in a further escalation, declared that it had begun levying transit tolls on vessels transiting the waterway. In addition, according to media reports,[i] it has also put forward four additional demands that could carry significant geopolitical implications.[ii]
Iran justifies the imposition of transit fees in the Strait of Hormuz by arguing that the vessels in question are operating within its territorial waters. Indeed, both Iran and Oman apply a 12-nautical-mile territorial sea regime in this strait. The narrowest point of the Strait is approximately 21 nautical miles wide, meaning that it is fully covered by the territorial waters of Iran and Oman. As a result, international transit passage is generally conducted through the median corridor between Iranian and Omani waters. However, this route has reportedly been closed by Iran. Oman’s territorial waters, on the other hand, are not sufficiently deep for heavily laden vessels, leaving Iran’s territorial waters as the only viable passage route. Iran has therefore begun to charge vessels for what it describes as “innocent passage” through its territorial waters, framing the payments as fees for security services provided to ships.
Moreover, Iran has not ratified the 1982 United Nations Convention on the Law of the Sea (UNCLOS) regarding transit passage through international straits, nor does it recognize its provisions as customary international law. According to Articles 37 to 44 of UNCLOS, the right of transit passage for ships and aircraft—allowing continuous and expeditious passage through straits used for international navigation—cannot be impeded or suspended by coastal states, even within their territorial jurisdiction.[iii] Iran, in turn, has closed off this median corridor, effectively leaving vessels with only the option of transiting through its own territorial waters in order to pass through the Strait. It has therefore begun levying transit tolls for such passage and has also started putting forward additional demands that could carry significant geopolitical implications. Iran, in turn, has closed off this median corridor, effectively leaving vessels with only the option of transiting through its own territorial waters in order to pass through the Strait. It has therefore begun levying transit tolls for such passage and has also started putting forward additional demands that could carry significant geopolitical implications. While managing U.S. foreign policy, President Donald Trump has generally approached bilateral relations through a realist logic, guided by cost–benefit calculations and the pursuit of strategic advantage. Iran, on the other hand, is described as continuously disrupting the conditions for negotiation by imposing preconditions aimed at gaining leverage, thereby contributing to the stalling of the diplomatic process due to the absence of perceived equal terms. Although the Trump administration seeks to secure leverage in the negotiations through the continuation of the naval blockade, Iran’s moves concerning the Strait of Hormuz are interpreted as an attempt to reverse this advantage, level the negotiating field, and potentially gain the upper hand in the evolving geopolitical balance.
In the current context, one of the most significant risks for the United States is the possibility that Iran’s practices regarding strategic straits may set a precedent for other countries. In this regard, Indonesian officials have stated that, although imposing transit fees on passage through the Strait of Malacca would be highly attractive, such a policy would be incompatible with international law and therefore will not be implemented.[iv] In the Strait of Malacca, the coastal states—Indonesia, Malaysia, and Singapore—have confirmed that no such transit fee will be imposed.[v] Indeed, UNCLOS constitutes one of the key pillars of international maritime law frequently invoked by Southeast Asian states, particularly in disputes concerning the South China Sea. Any deviation from its provisions could create inconsistencies with these states’ own claims regarding maritime jurisdiction in the South China Sea. International law is essential for all states and functions as a fundamental norm that must not be violated.
The selective application or violation of international legal norms may trigger not only a regional but also a global process of “norm erosion.” If Iran’s practices are adopted by other coastal states controlling strategic chokepoints, tendencies such as the expansion of de facto control over strategic straits, restrictions on passage, or the imposition of economic charges could become more widespread. Such a development could increase the costs of global maritime trade and lead to instability across multiple sectors, particularly energy supply security. Indeed, approximately 20% of global crude oil passes through the Strait of Hormuz, while around 29% transits the Strait of Malacca. Similarly, nearly 11% of global maritime trade passes through the Strait of Hormuz, compared to approximately 24% through the Strait of Malacca.[vi]These figures indicate that the Strait of Malacca is at least as strategically important as the Strait of Hormuz, and in fact may be even more significant.
The “transit passage” regime in strategically critical straits of international maritime navigation grants ships and aircraft the right of uninterrupted, expeditious, and non-suspendable passage. This regime, which has become part of customary international law, removes the authority of coastal states to arbitrarily suspend or restrict such passage. However, Iran rejects this legal framework and has effectively shifted the practice in the Strait of Hormuz onto a different footing. In particular, its policies aimed at restricting international transit through the median corridor have created a situation in which vessels are effectively compelled to use Iranian territorial waters. While this development represents, from a legal perspective, a de facto erosion of the transit passage regime, it also provides Iran with a significant instrument of control and leverage in political terms. As the United States seeks to exert pressure on Iran, the international system as a whole is confronted with a more complex and challenging landscape for global trade and maritime stability.
[i] “Iran has collected its first transit fee from vessels passing through the Strait of Hormuz”, Modern Az, https://modern.az/tr/dunya/596751/iran-hurmuz-bogazindan-gecen-gemilerden-ilk-gecis-ucretini-aldi/, (Date Accessed: 24.04.2026).
[ii] “While Trump’s blockade continues, Iran makes a striking move: four new rules regarding the Strait of Hormuz are on the table”, Türkiye Gazetesi, https://www.turkiyegazetesi.com.tr/dunya/trumpin-ablukasi-surerken-irandan-flas-hamle-hurmuz-icin-4-yeni-kural-masada-1786197?s=1, (Date Accessed: 24.04.2026).
[iii] United Nations Convention on the Law of the Sea (1983). “Article 37-44”, https://www.un.org/depts/los/convention_agreements/texts/unclos/unclos_e.pdf, (Date Accessed: 22.04.2026).
[iv] “Indonesia suggests charging a toll to transit the Malacca Strait”, Economist, https://www.economist.com/asia/2026/04/23/indonesia-suggests-charging-a-toll-to-transit-the-malacca-strait, (Date Accessed: 22.04.2026).
[v] “Indonesia says ‘no’ to UK-France proposed Hormuz naval mission”, AA, https://www.aa.com.tr/en/asia-pacific/indonesia-says-no-to-uk-france-proposed-hormuz-naval-mission/3916508, (Date Accessed: 22.04.2026); “Singapore, Malaysia and Indonesia ‘strategically aligned’ in keeping Strait of Malacca open: Vivian Balakrishnan”, Channel News Asia, https://www.channelnewsasia.com/singapore/strait-malacca-open-indonesia-malaysia-vivian-balakrishnan-6073151, (Date Accessed: 22.04.2026); “A toll on Malacca Strait puts Indonesia’s own legal foundations at risk”, Lowy Institute, https://www.lowyinstitute.org/the-interpreter/toll-malacca-strait-puts-indonesia-s-own-legal-foundations-risk, (Date Accessed: 22.04.2026).
[vi] “Chokepoint Warfare: After Hormuz, Could Malacca, Gibraltar & Red Sea Be Next as Iran Teaches New Tactics?”, Eurasian Times, https://www.eurasiantimes.com/chokepoint-warfare-after-hormuz-could-malacca-gibraltar-red-sea/, (Date Accessed: 22.04.2026).
