Six months into the war with Iran, it is worth taking stock of what has actually changed around the Gulf.

After Iran’s June 2025 missile strike on Al Udeid Air Base in Qatar, I argued that the years ahead would be more perilous for the Gulf and that deeper defence cooperation and integration would eventually become unavoidable. Earlier this month, I wrote here that the Gulf could no longer rely entirely on the old security toolkit and would need to build more of a security ecosystem of its own.  So far, events have borne out the broad direction of both arguments.

What has become clearer over the past six months is that the war is not simply changing defence budgets or generating new security agreements. It is beginning to change how Gulf states think about security itself: who they should work with, what they should expect from their partners and what cooperation needs to look like when a crisis actually begins.

Some of these changes are obvious. The war has demonstrated, in the most direct possible way, the vulnerability of cities, energy infrastructure, airports, ports and shipping lanes to missiles, drones and other forms of disruption. Threats that were often discussed in exercises and planning documents have become immediate operational problems.

For decades, Gulf security rested on a familiar structure: the United States provided the main external security umbrella, Gulf states maintained bilateral relationships with Washington and other Western capitals, and the GCC provided a regional framework in which defence integration remained uneven.

That system has not disappeared. Nor should it. The US remains indispensable to Gulf security and will continue to play a central role for the foreseeable future. What is changing is the assumption that this structure, by itself, is enough.

The war has accelerated the move towards a more layered security system. Gulf states are strengthening cooperation among themselves while deepening relationships with a wider range of partners. Turkiye is becoming more important. European states have greater potential to play an operational role. Existing bilateral military relationships are being asked to deliver more, while new regional arrangements are emerging alongside older ones.

The Mecca Joint Defence Agreement between Saudi Arabia, Turkiye and Pakistan is perhaps the clearest recent example. Its declaration that an armed attack on one would be treated as an attack on all immediately invited comparisons with NATO.

The principle itself is not new to Gulf security. The GCC’s existing Joint Defence Agreement already treats an attack on one member as an attack on all, a commitment GCC states have repeatedly reaffirmed during the current war. What makes the Mecca agreement different is that it extends this collective-defence logic beyond the GCC, linking Saudi Arabia to Turkiye and Pakistan.

The comparison with NATO is understandable, but it can also distract from what is actually happening. The Gulf does not need to reproduce NATO, nor is the wider Middle East particularly suited to one large security alliance built around a single hierarchy and a single understanding of threat.

The threat facing a Gulf state may come from a state one day and a non-state actor the next. Countries that see one threat in much the same way may have very different views of another. And no regional state, however capable, is likely to be accepted as the permanent political and military leader of every possible coalition.

What appears to be emerging instead is a system of overlapping partnerships rather than one grand alliance. Different countries will work together against different threats. Some arrangements will be Gulf-led; others will bring in regional or Western partners.

Such a system also requires a different way of thinking about leadership. A regional security architecture built around permanent hierarchy will always face resistance. Gulf and Middle Eastern states are protective of their sovereignty and bring very different capabilities to the table.

Leadership should therefore follow the threat. The state facing the immediate danger should have the leading political voice in setting the objectives of the response, the acceptable level of escalation and the use of its territory. But operational leadership need not mirror political hierarchy.

A maritime crisis may be best handled by the partner with the strongest naval capability. An air defence crisis may require the partner with the most relevant capabilities to take a larger operational role.

This kind of flexibility may be the only realistic basis for deeper security cooperation. But it depends on whether these overlapping relationships can connect when they need to.

This is where interoperability becomes important. If several countries agree that they will support one another in a crisis, can they actually do it? Can they share information quickly, communicate across their militaries, coordinate decisions and know in advance who is authorised to do what?

An attack on one country does not necessarily mean every partner must respond in exactly the same way. Support can take many forms, from intelligence, air defence and logistics to maritime protection or, in the most serious circumstances, direct military action. The clearer these expectations are before a crisis, the more credible the commitment becomes when one occurs.

There are already examples of what deeper integration can look like without requiring a large regional institution. Qatar’s military relationship with Britain has gone beyond the traditional buyer-seller model. British and Qatari personnel have trained and operated Typhoon aircraft together through the joint squadron, while Qatar and Turkiye have developed a combined military command structure.

These arrangements predate the current war. The UK-Qatar relationship, however, was also tested during it: in March, an RAF Typhoon operating with the joint squadron shot down an Iranian attack drone directed at Qatar.

Integration does not always have to begin with a treaty signed by ten countries. Sometimes it begins with two militaries learning how to work together properly.

Europe can play a larger role without replacing the US. Washington will likely remain the Gulf’s most important security partner while Gulf states build deeper operational relationships with Britain, France, Turkiye and other capable partners.

The past six months have strengthened the case for doing so. Gulf and European militaries increasingly face many of the same operational problems: missiles, drones, maritime insecurity, electronic warfare and threats to critical infrastructure. The next stage of Gulf-European defence relations should therefore be judged less by the value of contracts signed and more by whether their forces can actually work together when circumstances require it.

That means more exercises, embedded personnel and joint planning, as well as arrangements that allow bilateral partnerships to connect with wider GCC and regional structures.

The Mecca agreement will face the same test. Turkiye’s defence ministry has said that the three countries plan political and military coordination, joint exercises, air-defence cooperation and deeper defence-industrial ties.

For now, however, these remain plans rather than proof of operational integration. The agreement’s significance will ultimately depend on whether Saudi, Turkish and Pakistani forces develop habits of cooperation: whether they can share intelligence, coordinate air defence, sustain operations together and use defence-industrial cooperation to solve practical military problems.

Six months into the Iran war, then, the outlines of a different Gulf security architecture are beginning to appear.

It is unlikely to consist of one alliance, one leader or one definition of the threat. Nor is the Gulf abandoning the US or dismantling the security relationships that have served it for decades. Instead, a more flexible system is taking shape around these existing relationships: stronger Gulf cooperation, additional regional partnerships, deeper links with European militaries and a greater emphasis on whether countries can actually operate together.

Some of this momentum may fade if the immediate threat recedes. The challenge now is to make the lessons of the past six months durable. Ultimately, the test remains a simple one. When the next missile is launched, the next drone crosses a border or the next shipping lane comes under threat, can the countries concerned see the danger together, make decisions together and respond together?

If they can, then the most important legacy of this war may not be another treaty or another alliance. It may be the beginning of a Gulf security system that is more connected, more flexible and better suited to the region it is actually meant to protect.

The views expressed in this article are the author’s own and do not necessarily reflect Al Jazeera’s editorial stance.