A chorus of commentators has risen in the wake of Saturday’s attacks on Saudi Arabian oil facilities to insist that “the game has changed” — and even that this attack was the “big one” whose disruption of the global oil market makes escalation all but inevitable. But what is actually shown by these attacks is that the game changed long ago, and that new rules are desperately needed.

The attacks are just the latest episode in the long-running proxy war between Saudi Arabia and Iran. Though both Iran and the Houthis deny it, Tehran has long supplied the Yemeni group with missiles and other military supplies that the latter has used to strike Saudi territory. In response, the United States has supplied Saudi Arabia with weapons, refueling capabilities, and intelligence. It has also interdicted Iranian weapons and ammunition headed to Yemen. Moreover, the United States has imposed crippling sanctions that have led to 40 percent inflation and high unemployment rates, especially among youth.

Complicating this picture, there is evidence that Saturday’s attacks originated in Iraq, where Iran employs proxy militias, and not Yemen, as the Houthis have claimed. So not only do these recent attacks introduce new technology (long-range “bomber” drones) and raise the stakes (by denting the world’s oil supply), they threaten to drag even more parties into the conflict. If the attacks originated in Iraq, the Iraqi government will be forced to choose between taking greater, and potentially destabilizing, steps to rein in the militias — or risking attacks or other coercive measures by external actors trying curb Iran’s influence.

But all these complications do not change the fact that the proxy-war game changed well before last weekend. Iran’s proxy relationships have given it an extraordinary ability to impose costs on its adversaries while obscuring its role. Doing so allows it to manage its risks while politically constraining its adversaries’ response. It might seem intuitive to simply declare Iran responsible, and satisfying to retaliate against it directly. But international law sets a high bar for holding a proxy’s benefactor responsible for the actions of its proxy, making it difficult to build the kind of international consensus necessary to the legitimacy for any retaliation.

Under international law, a state is accountable for the unlawful actions of a proxy only if an organ of the state ordered the proxy to commit the act. It is not sufficient simply to have provided material support or even encouraged the unlawful act. For example, in the 1980s, the International Court of Justice found the United States not liable for Contra violations of international humanitarian law, even after concluding that the United States had “financed, organized, trained, supplied, equipped and armed” the Contras, even to the point of providing training materials that discussed “shoot civilians attempting to leave a town, neutralize local judges and officials, hire professional criminals to carry out ‘jobs,’ and provoke violence at mass demonstrations to create ‘martyrs’.” About a decade later, the International Criminal Tribunal for Yugoslavia found that the Federal Republic of Yugoslavia was responsible for atrocities committed by the Serbian Republic’s Army, but only because the FRY transferred officers to serve in the Serbian Army, paid their salaries, had the same military objectives, provided financial and logistical support, and “directed and supervised” Serbian Army activity.

Setting the bar so high establishes perverse incentives. A state that employs proxies is discouraged from moderating their behavior, since any attempt at moderation could imply effective control, and even from acknowledging the proxy relationships. So without proof that the Islamic Revolutionary Guards Corps, which typically manages Iran’s proxy relationships, ordered or participated in the attacks, there is little for which Saudi Arabia or the United States can hold Iran legally accountable.

This does not mean that the United States—or the international community at large—have no recourse to discourage Iran and its proxies from future attacks. In fact, the scope and scale of these attacks suggest a moment where the United States can, in fact, establish rules for the game in a way that sets conditions for the conflict’s eventual resolution. Here are some ways to seize the moment:

Manage escalation. Certainly Saudi Arabia has not just a right, but also a responsibility, to protect its energy and other civilian infrastructure. This right extends to conducting offensive actions against any actor who poses such a threat. However, escalation for escalation’s sake is self-defeating; it will simply make future attacks more likely. Thus measured military responses that focus on destroying Houthi missiles and drones are warranted. Of course, there are complications. The relatively indiscriminate means Saudis have often employed against the Houthis would only make things worse and would just increase calls for the United States to withhold support. Withholding of such support would, in turn, encourage the Saudis to simply use whatever means they have, regardless of how indiscriminate.

Instead, the United States has the opportunity to play a constructive and moderating role by providing intelligence and targeting capabilities to the Saudis to ensure that retaliatory strikes eliminate Houthi ability to strike and without doing excess harm. If Saturday’s strikes are proven to have been launched from Iraqi soil, then United States should provide similar assistance to the Iraqi government to prevent a reoccurrence. Of course, it will likely need to provide political cover, if not pressure, for the Iraqi government to act; however, it should avoid, as well as discourage, unilateral attacks on militias by any of its partners. Such attacks risk increasing sectarian tensions and destabilizing Iraq at a time when it is on a positive trajectory. That destabilization is in no one’s interest.

Politically and economically isolate Iran. Efforts to isolate Iran through sanctions and diplomatic engagement have so far proven ineffective in changing its behavior. Up to now, the other signatories to the Joint Collective Plan of Action have been reluctant to get in the middle of the recent escalation between Iran, the United States, and Saudi Arabia. And while current U.S. sanctions are hurting the Iranian economy, causing 40 percent inflation and ballooning youth unemployment, nevertheless the country remains trading partners with the United Arab Emirates, the European Union, and China, whose share approaches 20 percent.

Part of the problem is the United States’ “maximum pressure” policy resonates politically, but is not associated with a clear end state. As my colleague Chris Bolan observes, the United States has imposed “devastating economic pressure on Iran without providing leaders in Tehran with a clear roadmap for how to escape punishment.” More importantly, whatever end state the United States does articulate, it needs to be something the Iranian government can reasonably deliver. Forcing them to abandon the means they have to defend themselves without removing their perceived threat will continue to be ineffectual.

This point does not entail removing opposition to Iran’s ballistic missile or nuclear programs. However, Tehran’s greatest vulnerability is its economy, so any “off ramp” is going to have to provide some kind of economic relief. Alone, of course, economic relief will at best achieve temporary results, as it has in the past. However, this point is again where the United States has an opportunity to change the game. The impact of the current sanctions, combined with isolation by its traditional partners like China and Russia, as well as a military response to degrade its proxies capabilities would incentivize Iran to at least remove the threat they pose in Yemen.

Step up international efforts for a peaceful solution to the conflict in Yemen. As the point above suggests, Iran’s interests are better served by the perpetuation of the conflict in Yemen rather than its resolution, at least on terms anything the Saudis would accept. As long as the conflict continues, they have a relatively cheap way to impose costs on its major regional adversary. The political, economic, and military measures discussed here could change that calculation. However, if the international community does not also take the opportunity to invigorate a political resolution the civil war in Yemen, much of the potential for those measures will be wasted.

So, improve norms for proxies. Proxy relationships have been a feature of international relations for a very long time. States will use proxies as long as they reduce the costs and risks of force — and as long as international law and norms do not discourage their abuse. Coupled with technological advances that enable increasingly devastating attacks, we can expect proxies to stage increasing numbers of globally destabilizing events like the attack on the Saudi oil facilities.

But the shock of Saturday’s attack also represents an opportunity. The United States has a chance to really change the game by leading the international community in establishing norms for proxy relationships that encourages transparency and accountability. The first step towards such norms is to set the example. Doing so will require the United States to examine its own relationships, including that with Saudi Arabia, to ensure it plays a moderating, constructive role and does not enable further escalation or become a barrier to resolving the conflict. If we can get to that point, then the game will have indeed changed, and for the better.