Iran will pursue its nuclear quest although it has reaped few gains from a totem of national pride that has cost it well over $100 billion in lost oil revenue and foreign investment alone, two think-tanks said on Wednesday.

A report by the Washington-based Carnegie Endowment for International Peace and the Federation of American Scientists said Iran’s atomic work could not simply be ended or “bombed away” and that diplomacy was the only way to keep it peaceful.

“It is entangled with too much pride – however misguided – and sunk costs simply to be abandoned,” the report’s authors, Ali Vaez of the International Crisis Group and Carnegie’s Karim Sadjadpour, said of Iran’s five-decade-old nuclear program, which began under the U.S.-allied shah.

“Given the country’s indigenous knowledge and expertise, the only long-term solution for assuring that Iran’s nuclear program remains purely peaceful is to find a mutually agreeable diplomatic solution,” the report said.