Lock and Light gets in there with the bullshit analogy to nazi Germany.
How many countrys has Iran invaded?
Who are they thretening to invade?
Yes of course Iran wants the bomb - and in their strategic position (bordered on two sides by the very hostile, agressive and nuclear armed US and within range of Israeli nukes) they'd be mad not to. The US is desperate to stop them because it would make it very difficult to attack a nuke -capable Iran.
If you want a 1930s analogy - its like Germany trying to prevent Poland building an airforce.
They way to prevent them nuking up? Stop threatening them, stop sanctions and engage all regional powers (especially Israel) in a process to de-nuke themselves. This in turn would give progressive forces within Iran a chance to breath and make progress. Iran is not a monolithic police state (as Iraq was) - its a large, diverse country with lots of different factions and a certain level of democracy - but US sabre rattling merely reinforces the most reactionary and nationalistic elements.
The alternative to positive engagment is the present scenario where the US paints itself into a corner and ends up attacking Iran and quite possibly gets sucked into a war which they cant possibly win (short of carpet nuking persia) and will have appalling and wide ranging consequnces that will eclispse the current catostrophe that is Iraq.