During the 2026 Iran war, amidst joint US-Israel strikes on Iran, Iranian strikes against American and Israeli assets across the region, and the economic impact of the conflict, several surrounding nations began military mobilizations to secure their borders and maritime trade across the Arabian Sea, Red Sea and the Eastern Mediterranean, among others.
Western Bloc
Many Western countries have deployed ships to the Gulf of Oman with the goal of ensuring maritime security in the Strait of Hormuz, also serving as observers in the 2026 Iran war. France deployed the aircraft carrier Charles de Gaulle to defend Cyprus, with the intention of protecting French citizens affected by the regional instability, and to prevent a broader regional conflict that could threaten energy supplies to Europe. The United Kingdom deployed forces to reinforce its Overseas military bases in the Persian Gulf, while blocking US access to them for aggressive purposes. The Netherlands expressed interest in potentially joining the French and British mobilization in the Strait of Hormuz. Reports by Israeli sources suggest that Germany is planning for a possible military deployment in the Persian Gulf against Iran. Italy deployed naval vessels and air defense systems (potentially including SAMP/T batteries) to help protect the Gulf region against Iranian airstrikes, and also to protect Italian personnel and regional energy supply, while refusing to participate in offensive actions in support of the US and Israel against Iran. Ukraine has sent drone warfare specialists to US bases in Jordan, Saudi Arabia, the UAE, and Qatar to help counter Iranian Shahed drones. The Australian Government pledged to not send any ground troops to Iran and said that Australia would only take purely defensive action. Australia deployed forces to the United Arab Emirates (UAE) to defend the Gulf states and Australian military bases at the request of the UAE.
The European Council and the Gulf Cooperation Council made a joint declaration to mobilize forces with the intention to "work together on de-escalation, safeguarding regional security and respect for international law". France formed their own plans to assemble a multinational force (including Non-EU states) on a "purely defensive, purely support" mission to secure freedom of navigation in the Middle East and allow commercial vessels to continue transit through the Strait of Hormuz and the Gulf of Oman. Similar projects for multilateral mobilization have been planned by Italy. Iran warned NATO and the European Union against military activities in support of the US and Israel.
Regarding US efforts to re-open the Strait of Hormuz with the aid of NATO and other US allies, the United Kingdom and France have backed coordinated action to restore shipping without supporting US and Israeli attacks on Iran, while Spain, Greece, and Japan have ruled out military intervention. On March 19, France, Germany, Italy, Japan, Netherlands and United Kingdom declared their support to contribute in the efforts to open the Strait of Hormuz. Also did the European Union.
On 11 April, US Navy destroyers crossed the Strait of Hormuz, as they were challenged by IRGC naval forces. The incident was reportedly intended to show that the US will not recognize Iranian control of the Strait.
Eastern Mediterranean
In Cyprus and the Balkans
European Union and Britain
Following strikes on the island of Cyprus and the threats of the IRGC against the island, numerous nationsincluding France, Germany, Greece, Italy, Spain, the Netherlands and the United Kingdomdecided to mobilize their armed forces in the surrounding waters and onto the island, vowing to protect it in case of an attack. The European Commission Chief Spokesperson Paula Pinho stated that in the coming days following the attack, the EU "mutual defence clause will be up for discussion". On 6 March, Bulgaria allowed the United States and Greece to use its territory to counter potential Iranian attacks. The president of the European People's Party (EPP), Manfred Weber, called Iran a "criminal regime" and vowed that an attack on the Republic of Cyprus would be considered an attack on Europe. On 2 March, Emmanuel Macron (President of France) announced that simultaneous mobilizations were being conducted, which will include the temporary deployment of its nuclear-armed aircraft to 8 European countries (Germany, Britain, Poland, the Netherlands, Belgium, Greece, Sweden and Denmark) to bolster the security of the continent against spillovers from the 2026 Iran War and the Russo-Ukrainian war.
Iran's response was to state that such acts of involvement in the conflict could be considered "acts of war"; however, analysts note that the European mobilization in Cyprus was not the reaction Iran expected and seems to have worked as a deterrent. Observers in the countries of Cyprus and Greece noted how the war was perceived pretty vividly and fears of further escalation involving both nations are prevalent. Cyprus expressed worries of possible terrorist cells that could act within the nation on Iran's behalf from Northern Cyprus, where 10,000 pro‑regime Iranians live and where, allegedly, Hamas and the Muslim Brotherhood operate.
Italy's intelligence agencies reported that it is highly possible that the entire Eastern Mediterranean region will be affected by the growing instability in the Levant and the Strait of Hormuz, mainly suffering impacts on energy markets and supply security, which will affect Mediterranean countries and Europe as a whole if the Indo-Mediterranean trade route through the Suez Canal-Red Sea is damaged by the conflict. Such geopolitical possibility of maritime insecurity was declared as the main reason for various Western countries to deploy troops, with the main goal of protecting the Euro-Atlantic trade routes. Italian Prime Minister Giorgia Meloni has been developing a rapprochement between the European Union and the Gulf Cooperation Council for a common diplomatic strategy and maintaining their neutrality while condemning Iranian attacks.
Opposition to aggressive actions
Despite the mobilizations, there was no unified European posture in the conflict, with political divisions between an energic support to the Anti-Iranian military activities (e.g., Germany) and the development of a defensive strategy accompanied by distancing from—and sometimes condemnation of (e.g., Spain)—US and Israeli activities perceived as legally dubious. Protests started in Cyprus against the existence of British Cyprus bases, as the Cyprus–United Kingdom relations worsened, due to Cypriots fearing that the country could be dragged into the Iranian conflict if the bases are used for pro-US/Israel offensive activities instead of their declared defensive purposes. Similarly the Government of Spain protested and hardened its position against a more active European intervention in the Middle Eastern crisis, which damaged the Spain–United States relations after Pedro Sánchez condemned US-Israel actions against Iran as a violation of International law, declaring such actions as a "big error" which only developed a conflict that is foreign to Europe and is dragging the Eastern Mediterranean to instability, while denying the use of Spanish bases to the US and Israel armies. Emmanuel Macron and the European Commission expressed solidarity with Spain against the threats of US economic coercion against European military independence. Germany and Belgium also declared their opposition to deploying forces in support for the US-Israel aggressions. The EU has officially been calling for de-escalation and to prefer diplomatic initiative with the help of the Gulf Countries, adjacent regions in Africa and the Indo-Pacific that are also affected by the War.
Turkey
Turkey also expressed its worries about the insecurity for Turkish Cypriots, planning to deploy air forces to North Cyprus with the mission of provide more security to Cyprus island and avoid merging the Cypriot Conflict with the Iranian War. Also the Greece–Turkey relations entered in tensions due to their conflicting interests as both countries have taken advantage of the Iranian menace to deploy their armies near the Greece–Turkey border and to secure positions to aid the conflictive Greek Cypriots and Turkish Cypriots, as also both countries protesting against the other military movements while being reluctant to cooperate as NATO partners (even being denounced by Greeks that the Turkish government is secretly helping Iranians during the 2026 Kurdish–Iranian crisis and also giving help to Hamas against Israel through North Cyprus).
In the Levant
Syria
By Wednesday 4 March, the Syrian Army (already mobilized in the region before the 2026 Iran War, due to the Spillover of the Gaza war by the Israeli invasion of Syria and the Iran-backed Assad loyalist insurgency) has bolstered its troop deployments on the country's borders with Lebanon and Iraq, as also for giving support to the Lebanese government in the Disarmament of Hezbollah.
European Union At the start of the war, a projected 5 March International Conference in Paris to mobilize support to the Lebanese Armed Forces had been postponed. Despite, France mobilized forces in Southern Lebanon to aid in the peace process in the context of the Israeli–Lebanese conflict and redirect the efforts of the Lebanese government in the common goal of the Disarmament of Hezbollah, while also serving as a countermeasure to protect European interests against the non-agreed US-Israel military operations. The European Union itself on 10 March deployed emergency humanitarian aid for the civilian population harmed by the crossfire of the 2026 Lebanon war and its large scale displacements, with the help of the World Food Programme (WFP) and UNICEF. A day before, during the announcement of the mobilisation, the EU stated its desire for the respect of the sovereignty and territorial integrity of Lebanon by Iran-backed Hezbollah and Israel. Lebanon urged to European allies of Israel to send military aid for the stabilization of the region.
United Nations Since 2006, the United Nations Interim Force in Lebanon has been mobilized at the Israel Lebanon border as a peacekeeping force, aiming to support the Lebanese army's operations against Iran's sponsored terrorism by Hezbollah insurgencies, and to secure the Israeli withdrawal from Lebanon. Although UNIFIL's operations are scheduled to end on 31 December 2026, countries like Spain have declared that they will maintain their presence in the region in support of the Lebanese government and the Lebanese Armed Forces until conditions allow, given the escalating crossfire between Israel and Iran backed Hezbollah. Currently, UN forces have had to reinforce security measures to the maximum and remain "bunked" for most of the day to avoid being hit at the 2026 Lebanon war. Despite, recently have been proposals for an evacuation of the UNIFIL, with help of the European mobilized forces in Cyprus, due to the intensification of the hostilities in the region and the fears of institutional collapse in Lebanon.
Red Sea and Gulf of Aden
Houthi Yemen
The militarization of the Houthis (already engaged in the Yemeni civil war) has intensified as the Axis of Resistance links the Iran war to their ongoing Red Sea blockade by Israel, threatening to resume their shipping attacks if tensions escalate, while focusing to mobilize its forces to defeat the pro-US/Israel Saudi-led intervention in Yemen (not wanting to violate the 2025 United States–Houthi ceasefire).