Would Israel be able to destroy Iran’s nuclear capability? The Israeli prime minister, Binyamin Netanyahu, says all options are on the table. Strong words with only one real meaning - the military option.
Over the years I have spent many hours talking to defence analysts, pilots, government officials and experts in military strategy about what that military option might mean.
The Israeli Air Force does not have the capability to destroy all of Iran's nuclear facilities. Military officials and defence analysts have shown us that time and time again. Not even Israel's generals think it could be done. But that doesn't mean they can't mount some sort of offensive. But will they?
If Israel did attack, how would it get its planes to Iran? There are three routes the IAF could take.
1) Over Iraq. Iraq would find it difficult to stop Israeli aircraft.
2) Between Turkey and Syria then Turkey and Iraq, although it is unlikely Turkey would co-operate.
3) Over Saudi airspace. This is the wildcard. The Saudis are opposed to the warming of US and Iranian relations. But they will come in for huge criticism publicly at home if they allow Israel, with whom they have no official diplomatic contact, to use Saudi airspace. The Saudis could publicly condemn such an action while privately allowing it to happen.
In every scenario however IAF planes would need inflight refuelling. Most Iranian targets are 1500km away from Israel. That's a 3,000km round trip plus fuel for the operation and for contingency.
That's a massive operation in itself. According to publicly available data, IAF tankers would find it difficult to carry enough fuel for all the planes in the air as they only have eight to 10 refuelling aircraft.
There is an option of using an airbase in a neighbouring, friendly country. Azerbaijan has been mooted as one option. But according to one Iranian official I spoke to in Tehran in 2012 any landing of military aircraft in a neighbouring country would be spotted and therefore would alert Iranian defences.
So say the Israelis decide to attack. They refuel over the Mediterranean. They fly over Iraq, whose air defences and radar are no match for Israeli aircraft.
Israel would need to use GBU-28 bunker-busting bombs to destroy Iran’s hardened nuclear facilities. It has these weapons but they are, by their very nature, huge. Israel has only one aircraft system, the F15i, which can carry a bunker buster, and only one at a time.
Many targets. Not many planes.
In 1981 the Israelis hit and destroyed an Iraqi nuclear facility in a surgical strike. But that was a very different time, and a very different operation.
Hitting Iran's key targets would require sustained strikes over a period of time - perhaps weeks. And as soon as the first bomb hits the world would know very shortly afterwards.
Then there is the issue of Iranian air defence, in which the Iranians have invested heavily. According to the widely respected website AUSPower.net, the current anti-aircraft systems are robust and, with a mooted upgrade to the superior Russian S300, will become even stronger.
With a sustained attack, it is likely some of those IAF planes would get shot down. This presents Israel with an issue - what happens when the first downed IAF pilot appears on Iranian television? The Israeli military prides itself on its "no man left behind" policy.
As the twisted wreckage of IAF planes fills the world's screens, what does Israel do next? That's an unknown, I hazard a guess even for Israel. Certainly no one I have ever spoken to has been confident enough to tell me what options Israel might have then.
From the first strike, international outcry and condemnation of Israel would be swift. But Iran's nuclear programme would not be degraded. It's reactors would likely still be operating.
So Netanyahu finds himself in a position where one strike hasn't change anything, Iran has prisoners, and Israel is now number one bad guy in the world.
And how does Iran react? It has been developing missiles for years. A barrage against Israeli targets is within its capability. The country's hawks would be screaming for revenge and it is unlikely the leadership would sit back.
It also has the option of using proxies. Enter Hezbollah and Hamas. Then the IDF is fighting once more in Arab lands. How do you think that plays out?
And then there is blowback. Any Israeli aggression will further motivate Iran to develop nuclear weapons. After all, it has been hit despite trying to convince the world it was not making nuclear weapons. So why not just go ahead and make weapons? Israel has just made it clear they are a target either way - better to have nukes and not need them, than not have them and need them. It's a philosophy that's has worked for Pakistan and India.
This is all quite apart from the massive protests that will be unleashed by anyone who can write on a placard in the Arab and Muslim world. Despite Iran being a majority Shia country, an attack by Israel would also spur on groups who want to attack states or populations they feel are pro-US or pro-Israel.
In many ways, Netanyahu is right when he says that today the world is a much more dangerous place. He has always maintained Israel's security is key. But what lengths is he willing to go to achieve that goal?
This is simply one scenario deduced from my own research. By no means do I claim it to be definitive. No doubt, some will disagree. Any and all thoughts are welcome.
Follow Imran Khan on twitter @ajimran