Given the regime's renewed offensive capabilities, delaying foreign military assistance any further is a recipe for more rebel defeats.

The ongoing battle in and around al-Qusayr city in Syria's Homs province is not just another clash. It is a full-scale fight with major significance for the war, similar to the battle for Aleppo in summer 2012. Despite determined rebel resistance, this is a battle the regime must win. And given its current advantages, Damascus most likely will win. Al-Qusayr is already testing the regime's developing capabilities and those of its allies, especially Hezbollah. Perhaps more important, Bashar al-Assad's forces seem to be establishing a set of "Qusayr rules" that will shape how they conduct the war in the period ahead.

SIGNIFICANCE

The battle for al-Qusayr is important for many reasons. The area dominates the southern route through Homs province to the coast, a stronghold of the regime's Shiite Alawite supporters. It also controls the southern approaches to Homs city, where regime forces continue to struggle. In addition to threatening Shiite villages in the area, rebel control of al-Qusayr hinders regime access to Lebanon's Beqa Valley while facilitating the cross-border movement of arms to rebels in west central Syria. Victory in this battle would substantially improve the regime's position in Homs province overall, which is important for both maintaining access to the coast and securing the critical line of communication from Damascus.

The battle is also important politically and psychologically. For the regime, al-Qusayr offers a chance to display its strength to allies and enemies alike. A victory would boost its resilience and affirm the commitment of its supporters. For the opposition, defeat would increase internal tensions and raise doubts, with rebel factions blaming one another for the loss while wondering how they will be able to stand against the regime's growing capabilities. If Assad's forces are able to follow up with further successes, these effects will be multiplied.

Accordingly, the regime's goals in the battle have been to control the area and inflict a major military, political, and psychological defeat on the rebels. Although meeting these goals would serve the regime well at any peace conference, the battle began well before talk of Geneva II, and it is being fought for much more important reasons than negotiating leverage.

THE QUSAYR RULES

The regime's strategy for the battle has been to clear rebels from the countryside south and north of al-Qusayr city, isolate the area to prevent rebel withdrawal, bombard the city and environs to inflict losses and break resistance, and directly assault the city. To implement this approach, the regime has employed a combination of regular forces (reportedly including elements of the 3rd, 4th, and Republican Guard Armored Divisions) and irregular forces (the National Defense Army). Perhaps most important, it is using Hezbollah forces to provide reliable and effective infantry in the sustained and costly fighting. Opposition sources indicate that the regime has pulled regular forces from the Damascus area and as far south as Deraa province for this battle. Moreover, Assad's air and missile forces have intensively supported the ground operations; on May 29 alone, sixteen airstrikes and three surface-to-surface missile strikes were reported in al-Qusayr city. This combination of regular, irregular, and allied forces heavily supported by air and artillery is now the regime's formula for the conduct of the war.

At present, around five to six thousand government troops are involved in the battle, along with some two thousand Hizballah fighters. Each of these contingents has been reinforced in the past few days, reflecting the stubbornness of rebel resistance and the regime's need for a clear victory. Unconfirmed opposition reports have also claimed that Iranian fighters are involved in the fighting.

The al-Qusayr offensive is an operational-level action: Assad's forces are combining battle and maneuver to achieve strategic goals in the Homs theater of war. That the regime can conceive and execute such an operation at this stage of the war testifies to its resilience and adaptability, and to the unswerving support of allies Russia, Iran, and Hezbollah. Rebel forces have not yet shown the ability to respond to this kind of action, primarily due to command and organizational issues that make it difficult to concentrate and coordinate significant forces across provinces.

Specific regime tactics are also proving problematic for the rebels, though they have done better at this level. The regime has used its overwhelming firepower advantage to attrite rebel forces and slowly take ground. Although the opposition's terrain advantages and sheer determination have made this a costly process, regime actions now have a certain inevitability about them. Assad's forces simply keep coming -- assaults typically include heavy preparatory bombardment by artillery and air forces, infiltration of the objective area, and armor-supported infantry attacks. Surface-to-surface missile are used to strike rebel rear areas, crushing even the deepest shelters according to opposition sources.

Taken together, these "Qusayr rules" indicate how the regime will conduct the war going forward:

Combine regular, irregular, and allied units to achieve a reliable and effective fighting force

Isolate objective areas to prevent rebel reinforcement, resupply, and escape

Bombard objective areas with all available means to weaken defenses and increase the plight of any civilians trapped there

When an objective area includes rebel outposts and other outlying forces, drive them inward to compress the defenders

Conduct repeated assaults to seize key terrain, inflict casualties, and force defenders to use up their supplies

Exploit the regime's advantages in firepower and its ability to coordinate and sustain operations

Government and allied forces can be expected to apply these rules as long as they lead to success.

IMPLICATIONS

The regime has made slow but undeniable progress in al-Qusayr, inflicting significant casualties on rebel fighters and commanders despite its own significant losses and occasional local setbacks. Opposition forces in the area have been compressed into a shrinking pocket extending from eastern Homs province to al-Qusayr and its near surroundings. The city may not be completely and securely isolated yet, but that outcome is likely in the next few days. After that, it is only a matter of time before the city falls.

The strategy and tactics that are leading to this outcome say a great deal about the war's changing nature, particularly the regime's renewed offensive capability and increased reliance on irregular and allied forces. These factors will compel the rebels and their supporters to come up with the means of meeting the regime's challenge.

Nevertheless, this is not the last or decisive battle for Syria. For one thing, the rebels are having some success in other areas, including eastern Hama province, Deraa, and Aleppo. More broadly, battles in this war tend to have incomplete outcomes whose consequences erode over time. Both sides have difficulty sealing the deal and often find themselves fighting again on the same ground, as in Homs city, the Damascus countryside, and Aleppo and Deraa provinces. Al-Qusayr looks to be different, but that remains to be seen.

Whatever the case, the battle for al-Qusayr is significant in its own right, and for indicating how the war will now be fought. Given the results thus far, the rebels need to put their political and military house in order quickly. They need to show that they can either defeat these operations or make them so costly that the regime abandons them. Their foreign supporters should act soon as well, at least in terms of giving rebel forces the means for more effective resistance. The proposed peace conference may never happen and seems doomed to fail even if it proceeds, so delaying military assistance any further is a recipe for more regime victories.

Jeffrey White is a defense fellow at The Washington Institute and a former senior defense intelligence officer.