A rare moment of optimism.
Those caveats out of the way, there's also little reason to underplay the significance of the delicately brokered agreement, apparently overseen with great dexterity by Baroness Ashton, who was widely mocked and patronised when named as the EU's foreign policy representative four years ago. It is almost certainly the most significant agreement between Iran and the "great Satan" since the overthrow of the Shah, far outweighing the short-lived months of detente after 9/11 when Iran co-operated with the invasion of Afghanistan, before the country was named by President Bush as a member of the "axis of evil". The potential is clearly there if both sides really want it for a wider understanding and de-escalation, including in Syria, where the US and other Western countries have become involved in a proxy war between the Sunni and Shia Muslim states.
How much responsibility for the past decade of what often seemed like a gradual drift towards a strike on Iran's nuclear program can be placed on that Bush speech and the following war on Iraq is difficult to pinpoint precisely. The previous period of moderation under President Khatami was rewarded with what was seen by the clerical conservatives as the suggestion they were next on the list. In fact, the overthrow of Saddam Hussein gave Iran further influence, as still manifested through Nouri al-Maliki. It's only been a result of the ratcheting up of sanctions against the country over the nuclear program that it was seemingly decided by the highest authority in the land for moderation to be given another try through Rouhani, after reasonably free elections (if elections in which dozens of candidates were disqualified from running can be called free) resulted in his victory.
Also crucial it seems, alongside the secret meetings between the US and Iran dating back to March, was the deal on Syria's chemical weapons. The agreement on their destruction made clear how the US was prepared to step back from the brink when it seemed to be half-heartedly edging towards another conflagration. If John Kerry and Barack Obama were able to handle the embarrassment and brickbats of not going through on what looked to be a certain attack on Bashar al-Assad, drawing back from sleepwalking to striking Iran was always going to be far easier. The deal agreed upon also, as alluded to above, allows all sides to look the victor. Iran has effectively agreed to freeze its program in exchange for being allowed to exercise its rights under the nuclear non-proliferation treaty, to have a power capability but nothing more. The US is denying that's the case, but that's almost certainly the basis for the deal.
Perhaps just as important is how the deal appears to mark what could be the first sign of both Israel and Saudi Arabia having their bluff called. Binyamin Netanyahu has repeatedly overplayed his hand since once again becoming prime minister, at times treating the Obama administration as though the US was the minor partner in the relationship. Rather than tone down the rhetoric with the ascent to power of Rouhani, the Israelis have carried on as though nothing has changed, only to find Obama in his second term determined to take full advantage of the shift in Iranian leadership. Saudi Arabia meanwhile, still smarting from the US backing down over Syria, now finds its sworn enemy apparently having its role in the Middle East if not accepted, then at least recognised. It would be lovely to think this was down to the US finally realising that much of the funding for jihadists can be traced back to the country, as has been proved beyond any doubt in Syria, but one suspects it's more that drawing back from the threat of a strike was in everyone's interests.
This isn't to underestimate how solving the stand-off between the West and Iran is just one part of the current crisis in the Middle East. Regardless of how Assad now seems to have the upper hand in the civil war in Syria, the war there signifies how intractable and dangerous the Sunni-Shia conflict is, while the always with us issue of Palestine remains a problem for the world. The deal in Geneva does however give cause for optimism, the merest suggestion that the second decade of the 21st century won't be as disastrous or self-defeating as the first was. There's still a long way to go, but it's a start.