The airstrikes against the Houthis in Yemen are part of a broader self defense effort.Reuters

The Saudi-led coalition of 10 Arab countries, which is now intervening in the crisis in Yemen, is the product of longer-term efforts by Saudi Arabia to expand its military capabilities, build military coalitions with regional allies and ultimately play a more assertive role in the wider Middle East.
It comes on the heels of ongoing Saudi air force participation in airstrikes against the Islamic State (ISIS) in Syria, and reported Egypt-UAE airstrikes against Islamist militants in Libya in 2014. All these reflect the aspirations of leaders in the Gulf to reduce their longstanding dependence on U.S. security guarantees.
For years, many have written off Gulf militaries as mere consumers of expensive Western weapons—but this comfortable assumption may be about to change.
This is partly, but not only, about Iran. Certainly Saudi Arabia is concerned that if Washington approves a nuclear deal with Iran it will also be willing to accommodate Iran’s expanded role in the Middle East. Ever since the invasion of Iraq, Gulf leaders have felt the U.S. underestimates the risk of Iranian expansionism in the region.
More broadly, they question whether the U.S. will fully back them against other possible threats, including the Muslim Brotherhood or domestic uprisings. Thus, one of the early signs of the new foreign-policy assertiveness of the Gulf states was the financial support they gave Egypt immediately after the Egyptian army overthrew the elected Muslim Brotherhood president, Mohammed Morsi, in 2013.
The aid from Saudi Arabia, Kuwait and the UAE was more than three times the annual U.S. military aid to Egypt ($1.2 billion), ensuring that even if the U.S. had cut aid it would have had little impact. Another was the Gulf deployment in Bahrain in 2011.
Strengthening Gulf militaries is a long term project. Current efforts are heavily focused on their air forces, which are well equipped after decades of large-scale military spending: Saudi Arabia is now the world’s biggest importer of weapons.
Still, neither the airstrikes in Syria nor the UAE-Egypt airstrikes in Libya proved effective.
The Gulf capacity for boots on the ground is less clear. Saudi Arabia has sent ground troops to fight the Houthis in Yemen before, in 2009, after the militia had apparently made incursions across the Saudi border. Over 100 Saudi troops were killed. This is why it is a priority for Saudi Arabia to promote military cooperation with Arab and Muslim countries with stronger armies—such as Jordan, Egypt and Pakistan, which also need Saudi aid.
For its part, the U.S. supports more indigenous efforts to provide security for the region—at least, in principle. Washington is keen to see a greater role by allies that share a basic agreement on key interests. In effect, it is outsourcing intervention in order to avoid putting its own troops in harms way, and to avoid the delegitimizing effect of Western intervention in a region where the memory of the colonial period is still keenly felt.
Thus, it was a priority for Obama to ensure that Sunni Muslim nations from the Middle East would participate in the airstrikes against the Islamic State. The U.S. also welcomed Gulf military participation in the no-fly zone in Libya in 2011.
By contrast, in the cases of Egypt and Bahrain, cited above, the U.S. and Gulf interests were not fully aligned. The U.S. would have preferred to keep dealing with an elected government in Egypt, and was seeking to negotiate a government of national unity in which the Bahraini ruling family and opposition would both have had a stake. But neither of these cases fundamentally threatened core U.S. interests: Arab states are no longer likely to defend the Palestinians, for instance.
In the case of Yemen, it suits the U.S. for its Arab allies to take the lead. This comes at a delicate time for the regional balance of power, as the international talks over Iran’s nuclear program enter their final months.
The U.S. and U.K. have both supported the Saudi-led airstrikes, given that these are defending an internationally recognized president against a coup, and given that there were attempts to solve the problem diplomatically. But they are avoiding being seen as at the forefront of the move, and will be hoping that this does not derail their larger goal of nuclear talks with Iran.
Yemen’s Houthis are allied with Iran and Saudi Arabia tends to view them as an Iranian proxy. For Saudi Arabia, the Houthi coup in Yemen was a sign that Iran was threatening Saudi Arabia in what it sees as its own backyard. One of the messages Saudi Arabia wants to send Iran is that the country will respond assertively; that it is not the aging, brittle, ineffective state that Iranian rhetoric typically portrays it to be.
While the new king is 79, two younger-generation princes, the interior and defense ministers, are now among the most powerful people in the country—and the Saudi media has publicized their role in overseeing the operation in Yemen.
But the longer term Gulf game plan for Yemen is not clear. One of the criticisms of the U.S.-led coalition in Iraq is that they were far better at dismantling the state there than rebuilding it. While Gulf states are building up their aerial capabilities, their militaries have far less capacity to stabilize or rebuild.
Moreover, Yemenis will not necessarily see intervention by their neighbors as being more legitimate than Western intervention. In the case of Syria, the role of regional intervention—by the Gulf Arab states and by Iran—has proven profoundly divisive.
Relying too much on airstrikes has been a problem for the West. The Gulf is in danger of replicating Western failures.
Jane Kinninmont is deputy head of the MENA program at Chatham House, the Royal Institute of International Affairs.