Investing.com - Oil prices are likely to remain near a 3 1/2 year high as Mideast tensions and geopolitical risk remain high, as traders focusing on Iran as much as Syria.The immediate question is how Russia and Iran respond to the U.S.-led air strikes on Syria, following a week of political jockeying that sent pries up 16% from their February low. Traders, however, are also looking for signs as to whether the U.S. will abandon a deal with Iran, which removed international sanctions on the sale of oil in exchange for Tehran cutting back its nuclear programPresident Trump has until May 12 to renew or suspend sanction waivers under the deal the U.S and Iran signed in 2015.A decision not to renew the deal would reduce exports from Iran, one of the world's biggest oil producers. The big questions for the oil markets are just how much and how fellow OPEC members respond.