By Jonathan Marcus
BBC Diplomatic Correspondent
Two Israeli Sa'ar Five warships have passed through the Suez Canal
Earlier this week, two Israeli Sa'ar Five class warships - the corvettes Hanit and the Eilat, two of the most sophisticated vessels in Israel's small navy - passed through the Suez Canal into the Red Sea.
Late last month, an Israeli Dolphin class submarine, possibly also accompanied by other vessels, passed through the canal for a brief deployment in the Red Sea before returning the way it had come.
These are all very public deployments and for good reason.
These Israeli naval movements are intended as a clear warning to Iran that Israel retains military options should Tehran fail to halt its uranium enrichment programme.
An Israeli official is quoted in The Times newspaper as saying that the movement of the two missile boats should be seen as being linked to a future attack on Iran.
"Israel is investing time in preparing itself for the complexity of an attack on Iran," says the official. "These manoeuvres are a message to Iran that Israel will follow up on its threats."
Clearly any attack on Iran would in large part be carried out by the Israeli air force.
The Suez Canal is a vital waterway for cargo and military shipping
But the navy could play a part too. Israel's Dolphin-class submarines were designed to fire relatively short-range Harpoon missiles.
But they also have a number of larger-diameter torpedo tubes from which a much longer-range weapon might be fired.
There has been considerable speculation that Israel has designed a long-range cruise missile capable of being fired from the Dolphin boats, and that this might even have the option of being equipped with a nuclear warhead.
Israel's growing interest in Red Sea operations is not solely linked to the perceived threat from Iran's nuclear programme.
Israel is also increasingly concerned about arms smuggling into the Gaza Strip.
Analysts believe that much of the weaponry travels by sea from Iran to Sudan and then on to Egypt.
Last March there were unconfirmed reports that Israeli warplanes had attacked an arms convoy in Sudan.
All in all the Red Sea is fast becoming a more important area of operations for Israel's armed forces.
Nonetheless, Tehran remains Israel's central strategic concern.
A huge variety of preparations are underway for a potential attack against Iran's nuclear infrastructure.
There have been long-range large-scale air exercises over the Mediterranean. There are the recent naval deployments.
And the revelations concerning Syria's alleged nuclear reactor - with pictures of the installation taken on site - gave a tantalising hint of Israel's intelligence capabilities.
Academic and military experts have produced a torrent of reports about just how such an operation might be carried out.
But it is clear that Israel may have some surprises up its sleeve, and that its commanders intend to maximise their tactical options whether an attack comes from the air or from the sea.