In recent months, a rapidly growing number of Syrian activists, both on the ground and those in exile, have called forcefully and repeatedly for some form of foreign intervention, whether through the establishment of no-fly zones, no-drive zones, humanitarian corridors, "safe zones," or through the arming of rebel forces such as the Free Syrian Army.

The Syrian National Council, the most important Syrian opposition body and the closest analogue to Libya's National Transitional Council, has unequivocally called for foreign intervention. Its leaders have repeatedly issued such calls to the international community in similarly clear language. The same goes for Syrian activists on the ground. Each week, they agree on a theme for the Friday protests that take place across the country. On Friday, October 28, the protests were dubbed, again rather unambiguously, "no-fly zone Friday." We can't -- and shouldn't -- endorse something just because a country's opposition wants us to, but we do need to take their calls seriously, particularly because they happen to be directed to us.

As I argued in a recent article in The New Republic, Arab protesters and revolutionaries, despite their often passionate dislike of U.S. policy, continue to turn to us for support in their time of need. This should not be taken lightly. In a time when millions of Arabs are demanding and dying for their freedom, the United States finds itself in a privileged role. Because of who we are, what we claim to aspire to -- and, of course, our unparalleled military capability -- we often, for both better and worse, have the power to tip the balance one way or the other.

The clichéd refrain that the Arab uprisings are about "them" and not "us" seems to treat Western powers as innocent bystanders, which they aren't and haven't been for five decades. International factors have been critical in the majority of countries facing unrest, including Syria, Yemen, Bahrain, Libya, and, to a lesser extent, Egypt. In short, U.S. support for democracy matters and will continue to matter for the foreseeable future. In some countries, it will matter a great deal.

Some critics of the Libya intervention feared it would set a precedent. I hoped it would set a precedent -- that whenever pro-democracy protesters were threatened with massacre, the U.S., Europe, and its allies would take the responsibility to protect seriously, and consider military intervention as a legitimate option -- provided that those on the ground asked us to do so.

Unfortunately, one successful case of military intervention -- in Libya -- is not enough to establish a precedent. For too long, the Syrian regime has assumed, correctly it turns out, that Libya was the exception that proved the rule. Obama administration officials have said as much, insisting that the military option is not being seriously considered for Syria.