The Trump administration is again threatening economic strangulation and military action against Iran while holding out the improbable prospect of a quick “deal." Facing internal and external weaknesses, Iran may dangle tactical concessions on nuclear issues and seek to buy time, but it's unlikely to capitulate on its ballistic missile program or support for regional proxies, the backbone of its beleaguered defense strategy. US military action, meanwhile, seems unlikely to achieve the administration’s strategic objectives and risks igniting a regional conflagration, with a weakened Iran having vowed that the next round of conflict will be an all-out war.