Syrian protesters are reflected on a masked protester’s sunglasses as they chant slogans outside the Arab League headquarters in Cairo. (Amr Nabil -- Associated Press)

It has been eight months since the start of unrest in Syria. The United Nations said this week that more than 3,500 Syrians have been killed so far in the crackdown, and a peace plan advanced by the Arab League had barely come into effect before it fell apart.

The Syrian opposition is showing signs of impatience.

But any attempt by the Syrians to fuel an armed uprising threatens to divide the international community in its support for them and could be used by Assad for propaganda purposes, Jeffrey Feltman, assistant secretary of state for near eastern affairs, said Wednesday.

“We believe that, right now, [the demonstrators’] strength is in this peaceful protest – that they deny Bashar the ability to claim that he’s facing an armed insurrection,” Feltman told a subcommittee of the Senate Foreign Relations Committee.

The attacks against the Syrian government have so far been small in scale, and the uprising itself has remained largely peaceful. But, as The Post’s Liz Sly reported, there has been an increasing number of violent incidents, particularly across the north and central provinces of the country.

That, Feltman said, is exactly what Assad wants: for the opposition to “turn entirely violent.”

The question, however, is how long the protesters can hold out as a nonviolent movement, while being confronted with the brutal tactics of a government that Feltman described as a “family-led mafia.”

Just this week, government forces crushed opponents in a neighborhood of the center of Homs that had emerged as a key area of resistance.

The hope among U.S. officials is that financial sanctions and other efforts to isolate Syria – particularly with the support of Turkey – could become simply too much pressure for Assad to bear. And, on that front, U.S. officials say, the indications are positive.

Assad’s government is struggling to gain access to the international financial system. It’s drawing down quickly on its foreign exchange reserves. And its revenue from oil exports has all but evaporated.

Damascus, according to Luke Bronin, the Treasury Department’s assistant secretary for terrorist financing and financial crimes, is simply finding few willing buyers.

“The impact of these coordinated, multilateral measures has been profound,” Bronin said.