So far, public debate about the intervention in Syria has centered on the immediate scope and aims of any U.S.-led military operation, and whether the U.S. Congress should be involved. But no matter how the possible intervention and its aftermath play out, one thing is certain: the eastern Mediterranean -- where exploratory drilling has unearthed vast reserves of natural gas, and where competition over the rights to tap those resources is already fierce -- will become less stable.

For now, the least bad outcome seems to be a prolonged stalemate. And that is the most likely outcome, at least in the short term, if the United States indeed opts for limited military strikes. By definition, punitive cruise missile strikes seek to change an opponent's strategy without necessarily depleting that opponent’s capabilities. By raising the costs of bad behavior -- say, by damaging airstrips and bombing the presidential palace or other targets of value to the regime -- coercive air power is designed to make Assad’s generals think twice before contemplating indiscriminate tactics in the future. They would do little to end the war.

The regional implications of such a stalemate are not difficult to imagine, as they represent a continuation of the current state of affairs. With an average of over 100 reported fatalities per day, Syria would remain the most violent place on Earth. Sectarian fighting would continue to spill over into parts of Lebanon and Iraq. Refugee flows to Turkey and Jordan would continue. And Hezbollah and the al Qaeda–affiliated al-Nusra Front would be preoccupied with fighting each other rather than Israel or the United States, although they would gain valuable battlefield experience in the process.

The human costs of this scenario are staggering. Still, although a Syrian stalemate would not be helpful for economies in the region, it would likely be the least disruptive prospect for gas exploration in the eastern Mediterranean Sea. Exploratory drilling began off the coast of Cyprus in 2011 -- the year in which hostilities erupted in Syria. Since then, energy companies have adapted to a persistently unstable operating environment, and have been moving ahead with major projects. This June, the Greek Cypriot government signed a memorandum of understanding with two Israeli drilling companies on the construction of a liquefied natural gas terminal in Cyprus, with a final deal expected in December. As of August, Itera, a Russian gas pipeline company, has been in talks with Cyprus about supplying the country with natural gas on an interim basis before these offshore projects reach fruition.

From Israel’s standpoint, moreover, a Syria at war with itself is less likely to put its muscle behind Lebanese claims -- and Hezbollah’s threats -- on gas reserves in Israel’s exclusive economic zone. And from the standpoint of Nicosia, a Turkey preoccupied with fallout from the Syrian War is less likely to aggressively challenge the legitimacy of exploration in disputed Cypriot waters. In many ways, then, a stalemate in Syria has allowed regional energy projects to move ahead by distracting the actors most likely to oppose them.

Yet because an ongoing bloodbath in Syria would signal a failure of U.S. military intervention, if it gets involved, Washington could face strong political pressures to escalate beyond punitive strikes in an effort to tip the military balance toward the rebels. That cannot be accomplished with Tomahawk cruise missile strikes from navy destroyers and submarines, which are insufficient to degrade the regime’s conventional military capabilities. Instead, regime change would require a sustained strategic bombing campaign to neutralize Syrian air defenses, followed by close air support for rebel forces fighting on the ground. These efforts would need to be maintained until the rebels overrun the capital and eliminate the last pockets of loyalist resistance. Since Assad’s air defenses are considerably more robust than former Libyan leader Muammar al-Qaddafi’s, the United States would not be able to play second fiddle to the French and British in Syria, as it did in Libya.

Sam Pepple & Matt Baker / Sample Cartography

An expanded mission to remove Assad from power would not come cheaply or easily. Any military strike would almost certainly meet resistance from Syria’s air defense system and anti-ship missiles, although these capabilities have been somewhat depleted and are unlikely to have an effect beyond keeping naval activity further from the coast. To deter U.S. escalation, Assad might be tempted to utilize his main remaining source of coercive leverage -- a missile strike against Israel. To be sure, already stretched thin, a Syrian military already fighting rebels and the U.S. is unlikely to open a third front by attacking Israel. But such a Hail Mary pass will become more likely if Assad finds himself in a more desperate situation.

The prospect of such an attack -- however small -- has created new demands for Israel Defense Forces and new dangers for U.S. citizens and interests. To dissuade Syria from taking such a move, Israel has reportedly already deployed an “Iron Dome” missile defense battery near Tel Aviv, and tested its Arrow anti-missile defense system in the Eastern Mediterranean. A further impediment to regime change is that Assad is not as internationally isolated as Qaddafi, and his government’s capitulation is something that external actors, particularly Iran and Hezbollah, will actively seek to prevent. In fact, Iran and Hezbollah care much more about the outcome of the war than the West does, which should give the United States pause.

The extent of Moscow’s future involvement is more uncertain. Despite a series of recent high-visibility exercises in the eastern Mediterranean, the Russian Navy has no permanent presence there and does not have the assets in place to counterbalance the U.S. Sixth Fleet. Moscow might attempt a more limited operation to deter further escalation and resupply Syria from the sea -- in a replay of Cold War practice during the Arab-Israeli Wars. But long deployment distances and a lack of local maintenance facilities will make such an effort difficult to sustain. Meanwhile, if Russia meddles too much in the sea, the United States may use its presence to put heavy pressure on Israel and Cyprus to avoid partnering with Russia on future energy projects. Vladimir Putin is too shrewd a leader to embark on a mission with such high costs and low probability of success.

As morally satisfying as it might be, a rebel victory may be the most dangerous outcome of all for the eastern Mediterranean. Such a turn of events would open a security vacuum in a resource-rich and already volatile region. Recent experience has also shown that Salafi-Jihadist groups rarely demobilize after a war ends. Emboldened and battle-hardened, these roaming bandits prefer to expand their fight to other theaters -- be they Dagestan, Mali, or, now, Syria. From Israel's standpoint, too, an Assad regime preoccupied with domestic security may appear less threatening than an ungoverned space overrun by Sunni militias. For all his flaws, Assad -- like his father before him -- has been a relatively predictable and deterrable adversary.

The United States and its allies might thus seek to deny terrorist safe havens in the wake of a regime collapse, either through the use of unmanned aerial vehicles or the deployment of ground forces. But even in the highly unlikely case that the United States or local coalition members such as Qatar, Turkey, or Saudi Arabia would be willing to contribute troops for post-conflict stabilization, recent experiences in Iraq and Afghanistan are not encouraging. Such an effort may help the prospects of energy development in the Levant Basin -- mainly by redirecting the military activity of rebels and Assad loyalists inward, against occupying forces. But the low probability of this event, and the high costs of its success, make it a dubious benchmark for policy planning.

A third option is for the fighting to end in a victory for the regime -- the most likely outcome if the United States does not intervene. Over the last few months, as the Syrian Army and Hezbollah continued to make gains around key urban centers such as Qusayr and Aleppo, the momentum was clearly on the regime’s side. Significant parts of the country would likely have remained beyond the government’s control for months and perhaps years, but that would not have been unusual for a waning phase of a civil war. The possibility of Assad’s eventual triumph should still not be written off. Even if coalition efforts do go foward, the rebels could fail to capitalize on the international intervention.

A resurgent Assad regime would present innumerable challenges for the eastern Mediterranean. The regional balance of power would shift decisively toward Iran and Hezbollah, a development which will further aggravate the maritime security challenges facing Israeli offshore gas development. Many -- perhaps most -- refugees may resist returning to Syria for fear of persecution. Within Turkey, domestic tensions between a secular Turkish military and an Islamist civilian government are likely to escalate following an unambiguous foreign policy defeat, which will create incentives for Ankara to exploit Cypriot gas disputes for political gain. An Assad victory is also likely to inflict lasting damage on U.S. credibility and influence in the region, and its leverage in the mediation of regional disputes.

Whether the Syrian conflict continues in stalemate or ends in a rebel or an Assad victory, several developments seem all but certain.

The regional economy is set to take a big hit. Any escalation in the eastern Mediterranean will make it costlier for energy companies to operate there, more dangerous for commercial shipping to traverse local waters, and riskier for tourists to travel. Cyprus and countries like it -- reeling from a catastrophic banking crisis, highly dependent on tourism, and hoping to capitalize on newly discovered offshore gas reserves -- will face more hard times ahead. Southern Turkey will also become a riskier tourist destination, particularly if car bombings and other violent spillovers from Syria continue.

Some countries, though, may actually benefit from the instability. Fears that an intervention might disrupt energy trade in the Persian Gulf have already pushed the price of oil to its highest level in a year and a half. By helping to alleviate fiscal woes and enabling more domestic spending and investment, high oil prices are likely to boost the popularity of leaders such as Russia’s Vladimir Putin and to facilitate more assertive foreign policy -- as occurred following the 2003 invasion of Iraq. As one Russian pundit wrote, “the U.S. will get a new problem, and Russia -- new profits.” A similar dynamic may hold in other energy giants such as Iran, Saudi Arabia, and the Arab states of the Persian Gulf. Regional energy importers such as Cyprus, Israel, and Turkey will not be so lucky.

Commodity price shocks are unlikely to change the balance of power within Syria, where both sides receive support from major oil- and gas-producing states -- Iran and Russia supply the Assad government, and Saudi Arabia and Qatar supply the rebels. Yet windfall profits, even temporary ones, may escalate the conflict on both sides, since they will give patrons fewer incentives to support a peaceful settlement and the financial and political means to contribute additional assistance.

Meanwhile, Syrian civilians will continue to bear the heaviest burden. As demonstrated by conflicts in Sierra Leone, the Democratic Republic of Congo, and elsewhere, rebels with external support are less interested in earning local civilian support. The regime, too, has shown little concern about the population and will face pressure to make as many gains on the ground as possible while it still has the capabilities to do so. As the Kosovo experience has shown, all that may well increase civilian casualties in the near term.

No matter who wins the war, Syria’s forecast is bleak. At this point, the United States faces the question not of how to avoid the coming chaos but of how to contain it. A failure to respond to the apparent use of chemical weapons by the Syrian government would reduce future American threats and “red lines” to cheap talk that could readily be ignored. U.S. leverage in future confrontations over Iran’s nuclear program would have been greatly diminished. Equally troubling, U.S. inaction would leave governments and rebels in future wars with fewer reasons to limit violence against civilians.

Given all that, the best course of action for the United States -- in the sense that it is the least bad -- appears to be the much-criticized limited campaign of punitive strikes. To be sure, such a campaign will not end the Syrian war. It is also highly unlikely to change the behavior of combatants on the ground, apart from marginally reducing violence against Syria's civilian population, although even this possibility is uncertain. But on balance, a policy that preserves a tenuous stalemate will inflict less harm on the political and economic future of the eastern Mediterranean -- and at the cost of far fewer lives -- than any other alternative.