'National interest' is a bit like Gunnyl's Top of the Pops approach to greatness - at the time it merely means the benefits to be gained by those very rich who have most influence, and to hell with everyone else, particularly the future. Everyone's problems with Iran began when 'the West', particulary the UK, got rid of Mossadeq to prevent his nationalising Iranian oil and losing them profits, then replacing him with the loathsome Shah (I think the US confined itself to getting rid of the Tudeh Party), and destroying democracy. The result was that opposition moved into the mosques, giving us the problems we now have. Political interest led Carter to betray all he stood for by attacking Iran - an attack that was very possibly sabotaged - who knows?
'National interest', alas, means we are going to have more and more petrol crises as their view of US 'national interest' leads the oil companies to have the Empire spread and grow more oppressive from Palestine to Afghanistan and beyond. The British played the same game, move for move, back in the period after the First World War, and it is idiotic, like all such bullying. It broke down when Eisenhower had the guts to stop the prima-donna Eden in his fatuous Etonian tracks. 'National interest' is the interest of the nation as a whole, surely?
We pay twice as much for petrol as you do, and I have spent much more time than you queueing, jillian, I do assure you.