Syrian rebels' capture of oil fields

increases economic pressures

'Russia and China are Assad's strongest international backers and have used their veto power at the U.N. Security Council to prevent the international community from imposing international sanctions against Syria.
But Seifan, the Syrian economist, said it's unlikely international companies, even Russian and Chinese ones, will want to commit huge investments to any exploration now "because they don't know what the fate of the regime will be after few months." '