Besides the physical impossibility of such an invasion, as Israel does not have the tools or manpower to effect such an invasion (and there is also Jordan and Iraq in between), but even if Israel had the power to do so, they would not. The reason is that Israel is an expansionist state that occupies land to create a Jewish majority in such lands and then annex such lands. Somehow, I do not think it would be as easy to ethnically cleanse the 70 million Iranians, as it was to ethnically cleanse the Palestinians from Palestine in 1948.
So I guess Israel's only option would be air strikes. But I think Israel would think a thousand times before they enact such an option as it would have dire consequences for Israel, and likely would not even be successful at neutralizing Iran's nuclear capability. I think the most likely option is that the Israel lobby will continue its dirty games in Washington to make the US fight Israel's wars as they did in Iraq.
Any way, Iran is not doing anything in violation of the NRC rules, and everything she's been doing was under the eyes of the inspectors. Why do we want to prevent Iran from developing civilian nuclear technology? The oil and gas will eventually run out, and nuclear energy will be the alternative, and this is not very far in the future. Iran recognizes that and does not want to be a net energy importer in the future where it will be at the mercy of the industrial world, whom we know can milk third world nations very well whenever they have a chance.
Also why the hypocrisy? There is absolutely no evidence that Iran is building a military nuclear program. It is all speculation that Iran may in future convert its nuclear knowledge for military purposes. Well you could say for any civilian nuclear program. That is not an evidence that would stand in any just court. But the problem here is that the judge is also the opponent (as we say it in Arabic).
Then why don't we apply the same standard to Israel? Israel is not allowing any inspectors of its nuclear facilities. It is a known fact that Israel possesses nuclear arsenal (just not announcing them). Israel is a rogue state that has a very long history of attacking its neighbors. It is even said that Israel threatened to use nuclear weapons in 1973. Iran on the other hand has never attacked a neighboring country (1980-88 Iran-Iraq war was started by Iraq), and never even threatened they will attack Israel (unless they are attacked first).
So the answer to your question (What do you think we should do?) is nothing except making sure that Iran's nuclear program progresses under the eyes of the inspectors, and build trust with the Iranian government on this issue. Until there a hard evidence is found that Iran is developing a military nuclear program, there should be no talks of sanctions or threats of military action. That can only lead problems the region can do without.
The other thing that needs to be done is put Israel's nuclear program under scrutiny, and make Israel understand that the other countries in the region will be protected and covered by existing nuclear powers, so that Israel does not think of ever using its nuclear weapons first.
· 1 decade ago