Britain and the US are trying to get the rest of the permanent members of the UN Security Council to agree that Iran is in fact actively attempting to develop a nuclear weapons program. The hopes of this latest diplomatic initiative is to get Iran brought to the Security Council and to ensure that action will be taken against Iran by the UNSC. Convincing China and Russia of Iran's intentions are key as they would be the most likely to veto action by the Security Council against Iran.
My thoughts on this are that we're simply seeing history repeat itself as it did prior to the US invasion of Iraq. I'm not saying that the US is preparing to lead the charge into Iran, I would hope that logical reasoning and look at Iraq and domestic pressures would show that's not a viable option. What I am saying is that even if this does get taken to the Security Council, I wonder if some type of action be taken. No one argued that Iraq needed to comply with the UN and weapons inspectors, the trouble came in determining what to do and when to do it. When the UN didn't agree, the US, UK, and its "coalition of the willing" (don't forget about Poland) went their own way with it and invaded. There are greatly diverging views on how to deal with perceived threats to international security, and it doesn't seem clear that the UNSC will be able to be anymore decisive than it was leading up to the Iraq invasion. Can the UNSC tackle another major crisis over WMD and again run the risk of appearing irrelevant? Will squabbling be the end result of what to do with Iran? Once again the US is attempting to convince other states of the intelligence it and the UK possesses indicating a weapons program. Questionable intelligence will likely result in a divided response as it did with Iraq. Clearly the divide over Iraq still exists, and it seems unlikely that it will be bridged in the immediate future to the liking of all parties involved. Ultimately I believe that Iran will eventually be brought to the Security Council, but I question how effective a response will be enacted once the time comes.