Nothing better illustrates Israeli Prime Minister Benjamin Netanyahu's determination to condition his public to a unilateral strike on Iran than the obloquy visited this month by his circle on the – these days – popular state President Shimon Peres.

When Mr Peres dared to say publicly that Israel should only act in concert with the US, Israelis were told that he had a long history of misjudgments, including his opposition to the 1981 solo strike on Saddam Hussein's nuclear plant at Osirak.

Mr Peres is not alone, however. The public opposition to a strike by the immediate past heads of Mossad and the internal security service Shin Bet widely reflects similar views among most of the serving security establishment, excluding the defence minister Ehud Barak, but including the chief of general staff Benny Gantz. Given that Mr Netanyahu's record is that of a fairly risk averse Prime Minister, is he going to ignore their strongly held view that the benefits – a short delay in Tehran's nuclear programme of three years at most – are greatly outweighed by the dangers?

If not, Mr Netanyahu could be bluffing, course. The strike threat having helped to persuade the Western powers to tighten sanctions against Iran, he could even now be using it to tighten them further. The problem with the bluff theory – apart from what the writer David Grossman has called Mr Netanyahu's "messianic-catastrophic" belief that his purpose in life is to prevent an Iranian bomb – is partly one of raw politics. Might the Prime Minister not have a credibility problem if he were now to back off, with the issue, as Israel saw it, unresolved?

If he is not bluffing then the motives for a possible strike before the US elections are twofold. The military one is that Iran's nuclear installations, some deep underground, will soon enter what Mr Barak has called a "zone of immunity" – the point at which they become impervious to a unilateral strike by Israel, which lacks the deep penetration bombs the US has.

And the other is highly political, one opposition leader Shaul Mofaz has already accused Mr Netanyahu of harbouring, namely that President Obama might well be forced, against his better judgement, to back an Israeli strike in the heat of an election campaign. Certainly indications from those around Mitt Romney when he visited Israel recently were that he would not oppose a strike.

Mr Netanyahu has probably not yet decided to bomb Iran, any more than Iran has yet decided to build a bomb. And one reason the outcome is so hard to predict are the many variables ahead. One is the region's increasing instability, especially on Israel's northern borders. If Syria were to transfer chemical weapons to Hezbollah, both Israel and the US have suggested they would intervene. Israel might find itself so embroiled in a war with Hezbollah that it would delay opening a second front against Iran. On the other hand (and perhaps more likely) a war with Iran's proxies could rapidly expand into a confrontation with Tehran, including an Israeli attack on its nuclear facilities.

Another variable is whether Mr Obama would, as Mr Netanyahu would like, set a date by which the US would itself enact the military option unless Iran had agreed to halt its perceived march to "breakout" capability – when it could quickly build a bomb if it so decided.

Another possibility is that the President supplies Israel with the deep penetration bombs it lacks in return for a delay which would allow more time for sanctions and diplomacy to work. But for now at least, Mr Netanyahu, is keeping the world guessing.

Will Israel launch an attack on Iran?

Yossi Alpher: Former senior Mossad official and co-editor of the Bitter Lemons website

It is clear that they [Benjamin Netanyahu and Ehud Barak] do not have the majority of the public behind them. Bibi is a guy who looks at opinion polls assiduously... He doesn't want to lose the next election... The large majority of the security establishment is against them. The US is quite firmly against, [so] they have to bear in mind the possibility of serious disruption of Israeli-American relations. On the other hand, they believe in the necessity of doing it and they have been campaigning in recent weeks assiduously to persuade the security establishment, the public and the political establishment... Factoring in all these elements, I come up with just under 50 per cent probability that this will happen as matters stand today.

Nazenin Ansari: Iranian journalist, managing editor, Kayhan

If three months ago [the chance of a strike by Israel] was 70 per cent, now it is 80-85 per cent. The only way for the threat of war to decrease is a change of regime in Iran. Whether that takes place before war or after is the question."

Uri Dromi: Spokesman of Rabin and Peres governments (1992 -1996)

Ehud Barak and Benjamin Netanyahu... seem to be moving towards a strike despite of the advice of the military and the former head of Mossad... As things stand I would put it at 60/40 in favour of a strike.

Abdel Bari Atwan: Editor, al-Quds al-Arabi