Israel says it will defend itself against Iran - but its allies want to avoid a wider Middle East war
The Iranians are playing down the significance of what has happened in the central city of Isfahan overnight.
Officials are saying there has been no attack and state media outlets have posted jokey photos of miniature drones.
US officials say there was a strike, and that poses several questions. In particular, will hardliners in Iran's military want to push back? And does Israel have plans for more attacks?
This could be Israeli Prime Minister Benjamin Netanyahu's attempt to respond to Iran's unprecedented missile and drone attack last weekend without alienating US President Joe Biden any more than he has already.
Mr Biden had asked Israel not to respond to Iran's aerial assault and to "take the win".
Britain and other international allies of Israel have also called for restraint in public and through diplomatic channels.
If this strike on Iran is the extent of Israel's response there is a question over whether it will be enough for the former generals in Mr Netanyahu's war cabinet, who are believed to have pushed for a strong response.
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As they see it, a large response was needed in order to restore Israel's capacity to deter its enemies.
Mr Netanyahu's ultranationalist coalition allies have also demanded a fierce retaliation from Israel. One said the Israelis needed to "go berserk".
The best option for the region, in the opinion of western governments, is for both Iran and Israel to draw a line under the saga.
This flare up of hostilities started with Israel's attack on the Iranian diplomatic compound in Damascus, which killed senior military figures.
However, even if this is the end of this stage of this crisis, new precedents have been set.
Iran has hit Israel in a direct attack, and Israel has responded with its own direct attack.
That is a change in what is often referred to in the region as the "rules of the game" governing the long conflict between Iran and Israel.
The protracted clandestine war between the two countries has come out of the shadows.
