How long do you think it may be before we declare war on Iran & what do you think the instigating factor might be?

The industrialized nations have decided that Iran must be prevented from developing nuclear power (because Iran feels they have the right to have nuclear weapons) & most countries refuse to concede that Iran has the right to have nuclear weapons. So the US has instigated sanctions against Iran that are making things very hard on the Iranian people. They may retaliate by refusing to sell oil to the US or to other countries that have joined the ranks of those supporting the sanctions. Do you think it will be the refusal to sell oil to the US that may trigger the declaration of war? Or will it be some sort of ‘false flag’ operation? Right now it does appear that war with Iran is inevitable, & since they have some of the richest oil deposits in the world (a world that is hungry for oil), it does appear that it may happen soon, but when do you think it will happen & why?