JERUSALEM (Reuters) - Defence Minister Ehud Barak played down speculation on Saturday that Israel and US-led allies were waging clandestine war on Iran, saying sanctions and the threat of military strikes were still the way to curb its nuclear program. Barak was asked in an interview whether two explosions in Iran last month showed "the war has already begun" through sabotage. "I don't think so," he told Channel Two television. "I think that the answer to your question is negative." One of last month's explosions in Iran killed at least a dozen members of the Revolutionary Guards, including a general.