The passage of two Iranian naval vessels through the Suez Canal represents yet another clear sign of Tehran's widening strategic horizons.
This is the first time the Iranian navy has made such a deployment since the Islamic Revolution that overthrew the Shah in 1979.
Its significance is entirely diplomatic. But for Israel and main ally - the United States - it raises all sorts of difficult questions.
The two Iranian vessels - a British-built Vosper Mark 5 class Frigate thought to be the Alvand - and a replenishment ship, also British-built - the Kharg - do not represent any significant threat to either the Israeli navy or US vessels in the Mediterranean.
The missile-carrying frigate was launched in 1968. It is an impressive vessel by the standards of the Iranian Navy but no match for comparable western warships, nor the sophisticated missile boats of the Israeli navy.
Its deployment sends multiple signals:
- it demonstrates that Iran, too, can operate warships far from its own shores
- it underscores that if a significant number of Western warships can operate in the Gulf - which Iran sees as its maritime backyard - then Iran, too, can deploy vessels to the Mediterranean - which Nato countries would regard as their maritime backyard, too
- the Iranian ships are to be based at a Syrian port; thus solidifying and symbolising the close ties between Damascus and Tehran
- and coming at a time of significant turmoil in the region, the deployment illustrates that Iran is eager to secure its widening strategic interests. If this annoys the Israelis or the Americans, the Iranians may feel, then so much the better.
What's clear is that this deployment is not a direct response to the current upheavals in the Middle East.
Iran announced its plan to despatch some of its navy to the Mediterranean in January - well before the protests that have already swept the leaders of Tunisia and Egypt from power.
But - coming in the wake of these political changes - the Iranian deployment will be seen by the Israelis in particular as even more destabilising.
For all the Israeli unease, Iran is perfectly entitled to deploy its ships in this way.
Indeed given the terms of the Constantinople Convention of 1888 that governs transit through the Suez Canal, there was no real possibility of access being denied by the Egyptians even if they had wanted to.
Nonetheless for Israel, there could indeed be grounds for concern.
Iran has long been a supplier of weaponry to Hezbollah in Lebanon - the armaments coming via Syria. The Iranian replenishment ship can carry ammunition and cargo as well as fuel. Nobody has any idea as to what might actually be on board.
An Iranian naval presence operating out of Syria could also complicate any future maritime struggle off Gaza. Just suppose the Iranian frigate were to support a future flotilla trying to break the Israeli blockade; the danger of a potential direct confrontation between Israel and Iran is clear.
Back in January, the Iranians said that the deployment of their vessels to the Mediterranean would last for up to a year. It's by no means clear how much time they will spend at sea.
But the Israelis and probably the Americans, too, will be watching their movements closely.
For now the Iranian deployment is largely symbolic.
Last year the Russians announced that their supply and maintenance base at the Syrian port of Tartus was being deepened and modernised with the goal of hosting a permanent Russian naval presence after 2012.
So it looks like naval operations in the eastern Mediterranean are going to be getting a good deal more interesting.