BRUSSELS: On the second anniversary of the uprising that evolved into Syria's brutal civil war, leaders at a European Union summit Friday found themselves facing a difficult dilemma: trying to predict whether funneling more arms to rebels trying to overthrow Syrian leader Bashar Assad would save lives or result in more deaths.

In the end, the 27 national leaders were unable to reach a consensus and asked their foreign ministers, who will meet late next week in Dublin, to try to hash out a common position.

The argument in favor of sending arms, supported primarily by France and Britain, is that more arms will enable the rebels to protect themselves and the civilian population against the heavy weaponry of the Assad regime - and focus the minds of members of the regime on why they should negotiate a political solution.

The coalition "needs to have the means to defend the areas that have been liberated. What he is doing is committing a crime against his own people," French President Francois Hollande said, referring to Assad. "It has been two years of a terrible situation and the number of victims is rising daily."

That was a view shared by British Prime Minister David Cameron.

"Of course I want a political solution," Cameron said. "But this is not an either/or situation. I think we are more likely to see political progress if people can see that the Syrian opposition - which we have now recognized, that we are working with - is a credible and strengthening and growing force."

The argument against supplying arms to the rebels, supported by Germany and a number of other countries is that Syria is awash in guns and needs no more. About 70,000 people are thought to have died so far.

There are fears, as well, that more heavy weaponry would spark an arms race in the country, with Russia and Iran increasing the flow of munitions to the regime, and also that weapons meant for more moderate rebels would end up in arsenals of radicals.

"I made it clear that we have a whole series of reservations regarding weapons exports to the opposition because we have to ask ourselves whether we are not further fueling the conflict by doing that," German Chancellor Angela Merkel said.

In Vienna, Austrian Defense Minister Gerhard Klug said he was opposed to having the EU allow its members to send weapons to the rebels, saying they could find their way into the wrong hands. Austrian troops form part of the 1,000-strong U.N. peacekeeping force on the Golan, and the country's concern about the safety of its soldiers has risen since Syrian rebels temporarily detained 21 Filipinos last week.

Klug told Austrian state broadcaster ORF that EU arms deliveries "would mean more weapons in this crisis region," adding there was no guarantee about who would end up owning them.

The EU has in place an embargo prohibiting any arms from being sent to Syria, whether to the rebels or to the Assad regime. That embargo is scheduled to remain in effect until May, when it will either be renewed or allowed to expire.

Syria was not on the summit agenda - the main topic Friday was EU-Russian relations - but French officials had indicated that Hollande would raise it. And, while the divisions were deep, there was a desire to have the Europeans speak with one voice.

"We are all deeply concerned about the desperate situation in Syria," Dutch Prime Minister Mark Rutte said after the summit broke up. "Europe can only play a strong and effective role if it acts as one."

The effort to overthrow Assad's regime began as a popular uprising on March 15, 2011. Since then, fighting has spread across the country, claiming more than 70,000 lives and displacing nearly 4 million of Syria's 22 million people.