When U.S. President Obama met with Gulf Arab leaders last week, on April 21, it was all about the United States’ difficult relationship with those countries, in particular with Saudi Arabia. The perception that America was retreating from the Middle East, ready to desert its traditional Sunni allies after the nuclear accord with Shi’ite Iran, has kept the rulers of the six-member-strong Gulf Cooperation Council (GCC) obsessed. Europe, unsurprisingly, did not play a role in their discussions – except as a background foil for a discussion on a possible GCC-NATO cooperation.

Contrast this with the biggest ever EU delegation travelling to Tehran the weekend before. EU High Representative Federica Mogherini came with no less than seven Commissioners in tow, intent on developing a broad and comprehensive agenda for bilateral cooperation between the EU and Iran. Such partnership should build on the full and continuing implementation of the nuclear deal, the Joint Comprehensive Plan of Action (JCPOA), and extend from political and human rights dialogue to increased trade, energy, environmental, and academic relations.

Ironically, each meeting had its own proverbial elephant in the room. In Riyadh, Iran was not invited but ever-present as a perceived threat to the Arab states. In Tehran, the United States was not included but the most important absent actor: It is mainly the (non-nuclear) U.S. sanctions against Tehran remaining in place under the JCPOA that prevent Western banks – and thus, by extension, most European businesses – from re-engaging with Iran.

The bigger problem, however, is neither Europe nor the United States – nor, for that matter, an emboldened Iran that is still militarily much weaker than its Arab neighbors – but the ongoing uncertainty about the eventual effects of the Arab uprisings. When those movements did not turn out to be the “spring” that some enthusiasts had labeled them prematurely, many in the West discounted them altogether. However, not so the Arab rulers: From President el-Sisi of Egypt who is resurrecting Mubarak’s security state, to the Sheiks of the Gulf who intervene abroad to diffuse domestic dissent, leaders in the region ultimately fear for their own survival. 2011 taught them that the United States – at least under their current president – would not have their back in case of another popular mobilization. Moreover, America’s refusal to intervene in Syria despite those infamous “red lines” weakened any non-binding assurances that the Gulf Arabs might hope to receive from Washington. Some go as far as to argue that even a NATO-like defense treaty would have credibility problems at the moment (read: if offered by this administration).

It is also on the Arab uprisings where Europeans and Americans are yet to come together even half a decade later. They managed to agree on how to tackle Iran’s nuclear program through joint negotiations, though – which, given the stark transatlantic disagreements on this matter from the 1990s into the mid-2000s, is still surprising and already a success at the transatlantic level. Yet on an issue that should evoke broad support from Washington to Warsaw, i.e. supporting democratic transitions in the Middle East, the two sides have utterly failed to come up with a joint strategy.

This is particularly deplorable as the transatlantic partners also share the “realist” concern with regional stability, giving preference to dealing with the (difficult) rulers that they know than with whoever might emerge when, say, the Saudi royal family is gone. The combination of a value-driven impetus to support democratic movements and a calculated approach to stability and global power relations (mindful of how China and Russia might use a power vacuum in the region) should lead both sides to develop and implement a strategy of carefully building civil society and democratic elements in those countries while maintaining transactional relations with their rulers. Yet such transatlantic cooperation is still to emerge.

Given that, even with such a joint strategy, Europeans and Americans would still have to rely on some sort of acquiescence of the Arab potentates, why not start putting one’s own house in order first? The area where both sides of the Atlantic have most influence is arms sales. The United States exported arms worth $33 billion to GCC countries in the year following the Camp David summit last May. In 2014, Saudi Arabia alone has spent $80 billion on arms – more than either France or the United Kingdom. According to the World Bank, the top six arms-buying countries as a share of GDP include three GCC countries (Oman and Saudi Arabia as No. 1 and 2 as well as the UAE coming sixth), spending well above 5% of their economic output on weaponry each year. (The other three are war-torn South Sudan and Libya, as well as Israel).

While such business is obviously good for the American and European (and also increasingly Russian) defense industry, it also makes a violent confrontation in the Persian Gulf more likely – which is the last thing the transatlantic partners need.

As a consequence, the United States and Europe should coordinate to condition their own arms sales to Arab countries. The current post-JCPOA U.S. “strategy” of providing arms to GCC members with no strings attached to assuage their fears of Iran falls short of the (political) reassurances needed, while certainly increasing Tehran’s sense of insecurity. As a response, Iran is likely to boost its missile program as well as its capabilities for asymmetrical warfare.

In the end, arms supplies are not even a Band-Aid for bruised relations; instead they merely increase the regional security dilemma. Washington is already obliged to weigh its arms business with Arab states as to how it affects Israel’s ‘qualitative military edge’; extending such thinking to both the transatlantic level and to a common understanding of Gulf security would be an important first step. Moreover, the Europeans in particular should urge all Gulf states – including Iran – as well as Israel and Russia to sign and ratify the 2014 UN Arms Trade Treaty. (U.S. ratification would help.) This would not only be a strong symbolical signal but also effectively help regulate international trade in conventional weapons.

Finally, rather than aiming for the still far-fetched establishment of a regional security architecture in the Gulf, the transatlantic partners should work toward an agreement similar to the Conventional Armed Forces in Europe (CFE) Treaty signed between NATO and then-Warsaw Pact members in 1990. While this treaty has implementation problems of its own, its basic principle of mutual agreement on upper limits for conventional weapons in specific zones including reciprocal inspections would go a long way to defuse the simmering tensions around the Persian Gulf.

The more the transatlantic arms exporters are willing to do their share in increasing regional security, the more credible their efforts to lean on countries around the Gulf will be. Maybe Washington and Brussels could take the next trip to the region together.

This article originally appeared in Global Policy Journal.