(CNN)Countries are eager to buy Iran's oil, which tends to sell at a discount. The key player here is probably Beijing. As the West has shunned Iran, the country has deepened its economic ties with China. A 2012 Rand study notes that, "Over the past several years, China has become Iran's biggest oil customer and biggest economic partner." China could view the West's isolation of Iran as an opportunity to build a special relationship with it and develop that country's vast energy economy.
A nuclear deal with Iran is the best option
If, however, the sanctions can be maintained, Iran will be in trouble. Oil prices have halved and Iran is bleeding resources in Syria and Iraq (and Yemen, though considerably less there). Tehran is a proud, nationalistic country. It has withstood challenges in the past — during the Iran-Iraq war, it endured eight years of brutal conflict, chemical weapons attacks, and half a million dead — but the pressure will be real.
Would continued sanctions halt the nuclear program? That's highly unlikely.