Korea continues to dog America and the world. Vietnam, thanks to native will, intelligence and dedication has stabilised, (the defeat of China in 1979 was the cement). Iraq and now Iran will continue to be thorns and can ultimately lead to all out war in the region, if the situation is not handled properly and so far American policy has been short-sighted and driven by emotion rather than its real interests.
America's entanglement with Iran began with its collusion with the Brits to bring down the democratically- elected government of Mossadegh in Iran in 1953, over his plan to nationalise the oil industry, which had been dominated by Britain (Britain had invaded Iran from the south and Russia from the north, in the early 1940's to prevent the Nazis from taking control of the oilfields. The Russians withdrew after the war but Britain stayed but needed American resources to hold on, as they no longer had the means to do so. India, its "jewel in the Crown" was gone and its other colonies were clamouring for independence). The Shah (who had been selling shoes in Italy) was put on the Peacock Throne and propped up, mainly by the Americans. His autocratic and corrupt rule was ended by the Ayatollah's religiously- driven revolution and America lost an important ally, its embassy was breached and hostages were taken and held for 444 days, while it stood by impotently. It has not been able to get over this and so supported Saddam in his 8 (1980-1988)-year war against Iran, which bled and weakened both sides and eventually led to Saddam being suckered to invade Kuwait and then being invaded, arrested and killed. Iran has since regained its strength and now dominates the Iraqi government, threatens Israel and trying to build its own "bomb".
The past thirty years has seen America stumbling to find the correct approach. From the enmity of the Ayatollah to the moderation of Rafsanjani to the irratation of Ahmedinejad, no clear/consistent policy has emerged. Even Obama, who first try to engage and then changed his mind, unduly influenced by Israeli lobby and its supporters in the State Dept. still bitter about the past.
America must understand that Iran is a major player in the region, and that it needs Iran in at least four areas. Firstly Iran share /meet borders with Afghanistan and Pakistan at Baluchistan. This is a crucial area for drug-trafficing, weapons smuggling and access by Islamic militants going to and fro, to Pakistan and Afghanistan. Iran's co-operation can go a far way to neutralise this area/flow. It had been working with the American DEA and this must continue. Secondly, Iran has great influence with the Shia government of al Maliki in Iraq (60% of Iraq's population is Shia and many of the Shia leaders had lived for years in exile in Iran, the major Shia nation in the world). There will be over 17,000 Americans diplomats, CIA, DEA, contract workers in Iraq and Iran can be very useful as far as their safety and America's continued interests. Thirdly, Iran controls Hizballah, the major military force in Lebanon (which drove Israel out of Lebanon and continues to be of concern). Iran's help will be needed to handle Hizballah in any confrontation with Israel. Fourthly, Iran also can be of use in Syria where it is close with the Alewite(minority) government of Assad. Here Iran can be used to influence Assad's policy at home and also in Lebanon and with Israel.
Sabre-rattling is not the answer. Iran can be brought into the fold. There will be concerns, given the past histroy between the two countries, but this can be overcome with time and diplomacy. Obama was right the first time, but pressure from the Israeli lobby and the war-hawks on both the Democrats ( Schumer etc.) and Republicans (Mc Cain etc.), together with the on-going presidential election (where he cannot appear to be soft, especially given the raw emotion associated wit Iran), mean that there will be more threats and counter-threats (what with the military exercise and the threats to close the Staits of Hormuz, by Iran). Israel has also been talking about striking Iran's nuclear facilities.
These are dangerous times and the tough talk on both sides make the possibility of war, very real.