Libya and Syria have become the poster children for the varied impacts that the so-called Arab Spring have had on the Islamic Middle East. They are not the most important countries to have undergone changes (Egypt, the outcome of whose upheaval remains a work in progress, can claim that distinction), but they do represent the most polar outcomes that the popular uprisings have produced to date. In Libya, the rebels–with the generous and probably critical assistance of Western militaries–have succeeded in dislodging long-time ruler Muammar Gaddafi, whose whereabouts remain a mystery of the Carmen Sandiego variety at this point. In Syria, the regime of Bashar al-Assad remains in power in the face of worldwide condemnation but little effective action, and seems likely to remain so for the foreseeable future.

The countries and their situations are a study in similarities and contrasts. Both are, of course, majority Sunni countries (as are most Muslim states), both have a diverse population that is tied together by common religion, both have long-standing traditions since achieving statehood of authoritarian rule in which the military has played a prominent role, and both have ties (admittedly of different varieties) to international terrorism. On the face of it, Syria is in many ways the more important country by virtue of population (22 million to 6.5 million) and strategic location: Syria has long borders with Iraq and Turkey and less lengthy borders with Lebanon, Jordan and Israel, whereas Libya borders six North African countries, the only one of which that has strategic significance being Egypt.

There is, of course, one very significant difference between the two which explains the highly differential way the international community has reacted to demands for political change in the two countries. That difference, of course, is that Libya has a large amount of very desirable petroleum, and Syria does not. The contrast is enormous. Using CIA World Factbook figures, Libya exports approximately 1.5 million barrels a day (15th largest in the world), while Syria exports 155,000 barrels a day, about one-tenth of the Libyan figure and 56th in the world. Known Libyan reserves stand at 47 billion barrels, compared to 2.5 billion for the Syrians. Moreover, Libyan oil is relatively cheap to extract and is particularly “sweet” (low-sulfur content), a particularly important factor for Europeans who have geared their refineries to processing sweet crude and can only deal with other oil with considerably more difficulty and expense.

Oil production has driven the economies of the two countries in opposite directions. Libyan GDP per capita, for instance, is about $14,800 (84th in the world), and while it is distributed in an inequitable manner of which the Tea Party would be proud and Ayn Rand disciples envious, it is considerably higher than in Syria, with a per capita GDP of $4,800, 151st the in the world. Prior to the revolution, Libya was a classic “petrolist” state (to borrow Thomas L. Friedman’s term), where huge oil revenues (95 percent of export earnings, 80 percent of government revenues) were used to buy off the population and blunt its democratic urges. Petrolist success took a hit with the success of the revolution in Libya.

Libya has succeeded in throwing off its shackles for the moment, and Syria has not. The outcome in Libya is far from ordained, and could vary from a total democracy to the rise of a new dictator: prudence suggests somewhere in between, whatever that may mean. The al-Assads cling to power, and despite universal pleas for them to cease their repression and to step down, Bashar al-Assad shows no indication he will do either. Nobody wants to talk about his success in holding power, but it is not unlikely, at least in the short run.

The key element in Libyan success and Syrian failure is outside pressure. Put simply, it is highly unlikely that the Libyan rebels would have succeeded without the covering air power of NATO to suppress government forces (attacking them directly, preventing their forays against rebel units in the field intent on their destruction). These rebels, it must be remembered, were a pretty woebegone, rag-tag coalition when they began, and the early prognosis for them was not good until NATO airpower shifted the balance of power. There has, to put it mildly, been nothing like that in support of Syrian dissidents who are, as best one can piece together from media reports, been treated much more harshly than the Libyan government treated its citizenry. Why the difference?

The answers, of course, are pretty obvious. The first and overwhelmingly most important is that Libya has something the outside world wants (oil), and Syria does not. This makes Syria, despite its geography and demographics, much less important to the world–and specifically to the countries that can militarily interfere–than Libya. The fact that Libya is a short and undefended flight across the Mediterranean Sea from Libya and that effective assistance did not include putting boots on the ground (sand?) and thus creating the possibility of many casualties, added to the ease of making the decision to help Libya but not Syria. Any actions against Syria are likely to have to come from neighbors, who show neither the interest nor capability to tangle with the regime in Damascus. Human rights violations alone are simply not enough.

The other element has been that the coercive capacity of the Syrian government has proven more capable and resilient than that of Libya. On the face of it, the Libyans has the wherewithal to expunge the rebels but could not. Part of the reason was geographic (target cities were fairly far away), and traversing the terrain meant crossing open territory and being left vulnerable to NATO air power. Partly, however, the Libyans seemed less capable (ruthless, blood thirsty)than Syrian forces). For the time being, Syrian brutality has succeeded; it may not in the longer run, but for the moment, the Syrians have held the line.

None of this suggests how the revolutions in either country or the region will come out. There are simply too many variables, some foreseeable and others not, that could influence the ultimate outcomes. Roughly nine months after the Arab Spring erupted in Tunisia and spread through the region, however, the experiences in Libya and Syria do suggest the range of possible outcomes.

Donald M. Snow, Professor Emeritus at the University of Alabama, is the author of over 40 books on foreign policy, international relations, and national security topics. This essay first appeared at his blog What After Iraq?.