We will probably never know whether Bashar al-Assad lost any sleep over the horrific chemical weapons attacks he allegedly ordered during his country’s ongoing civil war. But Syria’s president has probably already taken solace in the fact that, despite the hundreds of thousands of Syrians who have lost their lives in the fighting, things could have easily gone worse for him personally. With insurgents losing ground to the regime’s forces and succumbing to ever more infighting among themselves, it seems increasingly likely that Assad will avoid losing the war -- which will qualify, in this context, as an outright win.

For the many countries, including the United States, that have based their policies on the hope that Assad would eventually be forced from power, Assad’s resilience has probably come as a disappointment. (But given their generally indecisive interventions in the war, the outcome should not come as a shock.) Nevertheless, Washington and its allies need to reckon with the bitter trajectory that Syria is now on. The regime that emerges from the civil war will be more oppressive and more anarchic than the brutal yet stable one that existed before the war.

First, it is important to understand what victory will mean. In order for Assad to consider himself the winner of this conflict, his forces would need to gain control over the 40 percent of Syrian territory, concentrated in the western part of the country, where 60 to 70 percent of Syrians live. (A key military objective will be to secure the M5 north-south highway that connects Damascus to Homs, Hama, and the hotly contested city of Aleppo.) At the same time, Assad would need to clear out pockets of resistance behind the regime’s main lines. (This is exactly what he has already achieved in Qusayr and the area around Homs, giving his fighters unimpeded access to the Bekaa Valley and Hezbollah-controlled areas of Lebanon.) If Assad achieves all that, he will have gained a secure hold on his rump state for the indefinite future -- and a favorable position in any eventual negotiations with the opposition.

Of course, if Assad manages to stay in power, his level of control over the country will never again be what it was before the war. In part, that is because his government's geographic reach will be curtailed: Parts of the country (particularly in the northwest and along the Euphrates River) will remain under the control of the Syrian opposition -- including organized terror groups -- even if they have given up the immediate goal of toppling the Assad regime.

Even in those areas where Assad maintains control, his authority will be greatly diminished. He has waged all-out war against his own country, resorting to the use of Scud missiles and chemical agents against civilian populations. Those tactics may have helped him stay in power, but they will also cost him every last shred of popular legitimacy.

In turn, Assad will increasingly resort to brute force to demonstrate his authority to Syrians. His postwar reign of terror will likely target the majority Sunni population that has directed the uprising against him. The formerly “liberated” areas of Syria will probably have the most to fear. If the regime makes an effort to retake these areas, even temporarily, it is easy to imagine thousands of Sunnis being rounded up and subjected to the nation’s archipelago of prisons and torture chambers. And that will likely lead to waves of refugees fleeing for safety to other opposition-controlled areas in Syria or to neighboring countries.

Any such campaign of sectarian cleansing would shape the entire region in new ways. Assad would likely rely on the shabiha, Alawite militias supported by Hezbollah and the Iranian Revolutionary Guards, to carry out his oppression; over the course of the war, these militias have proven more reliable than Syria's traditional security agencies at laying siege to opposition-controlled pockets in Syria. (The shabiha have already been used to displace -- and, the opposition alleges, massacre -- Sunni Syrians in Homs and the adjacent Orontes Valley.) In other words, Syria would be drawn into deeper alliances with Iran and Hezbollah. In response, Sunni countries in the region would probably try to support a continued Sunni insurgency -- even if that meant relying exclusively on jihadists with their own agendas.

The upshot: Iranian and Hezbollah forces will probably remain in Syria indefinitely, permanently institutionalizing what had originally been an ad hoc arrangement. And the foreign-supported Sunni insurgency, mired in a stalemate with Assad, would likely begin to focus on international terrorism. It is unlikely that Syria’s secular opposition would find an amenable home in these ungoverned spaces; those who manage to evade torture or death at the hands of the Assad regime would try to form their own enclaves, or join the waves of refugees forced into exile.

There is also the question of how Assad would try to repair Syria's destroyed economy. According to a study by the Syrian Center for Policy Research, total losses of the war are estimated at $85 billion, $40 billion in the first quarter of this year alone. The Syrian regime has burned through a lot of the estimated $17 billion in hard currency reserves it held at the beginning of the uprising, to compensate for combined U.S., EU, and Arab League sanctions on Syrian oil production -- measures that are unlikely to be lifted even if Assad holds on.

To keep its head above water, Damascus has reportedly received up to $500 million per month and lines of credit from Tehran to finance food and oil imports. That dependence would undoubtedly grow in the years ahead. The Central Bank of Syria, reportedly with help from Russia, has also resorted to printing money, spurring monthly inflation rates of close to 35 percent. Extreme poverty -- the milieu in which extremists thrive -- would continue unabated.

So any thought that an Assad victory will lead to stability in Syria should be tempered by the realization that he will be abjectly dependent on other countries for security and money. And that reliance will produce plenty of instability. The reconstituted Assad regime would be particularly beholden to Tehran, which would dramatically expand Iran's influence in the region and make it increasingly likely that Syrian and Lebanese territory would be used to confront Israel and other U.S. Sunni allies.

Meanwhile, Syria's ungoverned spaces would become havens for Sunni or Kurdish extremist groups, akin to the lawless areas in Somalia where the al Shabab terror group operates. Even worse, these havens would be in areas adjacent to Israel’s borders, adding to Jerusalem’s always growing list of problems. And if Assad manages to maintain his authority in most of Syria, Israel could become an even more attractive target for those extremist groups and their sponsors.

The most realistic scenario, then, for a postwar Assad-led Syria is a state in which multiple sponsors of terror -- Assad himself, the Iranian regime, Sunni offshoots of al Qaeda -- are simultaneously pursuing their own ends alongside one another. It would likely be the source of instability, as well as the site of brutal crimes against humanity, for years to come. That's why it is in the West’s interest to prevent Assad’s survival by ordering airstrikes on regime targets, pressuring Moscow and Tehran to stop supporting him, and aiding moderate members of the Syrian opposition. Otherwise, the only upside of Syria’s future will be that that it will finally put the lie to the adage ”Better the devil you know than the devil you don't.”