Juan Cole, noted Mideast expert, points out that in order to make a nuclear bomb, one needs "about 16,000 small centrifuges hooked up to cascade." to achieve the necessary 80% enrichment. Iran possesses 180 centrifuges hooked up to cascade and can reach a purity of 3.5%. In other words, Iran can make glowing Mickey Mouse watches (Which the US used to do back in the 1950s).
Cole believes that Ahmadinejad and Bush are both using each other as boogeymen to frighten their countrymen because both groups of hardliners are low in popularity.