Iran shares no border with Syria, but Syria is a neighbour and an ally. For Iran, the situation is serious. There are fears of a spreading war, of impending regional disaster.
The message from Iran since the beginning has been one of solidarity and against foreign intervention.
Iran supports the new proposal to put Syria's chemical weapons under international control and has wholeheartedly condemned the use of chemical weapons in Syria. It does not dispute the weapons were used, but does question the allegations about who used them.
Change in tone
Iran has not wavered from its stance since the beginning of the conflict in Syria two years ago. But there is a change in tone and there are internal developments.
The biggest come from the Foreign Ministry and its new minister, Mohammad Javad Zarif. The new president, Hassan Rouhani, has emphasised diplomacy and better foreign relations.
One very important development supports this promise – nuclear negotiations will now be handled by the foreign minister, not the secretary of the Supreme National Security Council, which has been the case in the past.
This points to the fact that Rouhani intends to use the foreign ministry and its influence to greater extent. That does not only include nuclear talks but the Syrian issue.
Perhaps the biggest warning against military intervention has come from Zarif, who, speaking at a press conference in Baghdad this week, said: "Iran is making every effort to prevent a war in the region… the drums of war are beating," and warned, "the flames of any possible military intervention would engulf every country in the region".
As for the comments from Obama about military options, Zarif retorted: "I do not know why those who say all options are on the table do not understand the fact that civilised countries 65 years ago… rejected, in the charter of the United Nations, the use of force as an illegal practice." He made those comments in Farsi, Arabic and in English.
This is the change in diplomatic practice – putting the well-connected Zarif at the forefront of Iran's messages and positions.
His stance is supported by different elements in the Iranian government, including Alaeddin Boroujerdi, the chairman of Iran's National Security and Foreign Policy Commission. He reiterated this week in Damascus that the Syrian crisis should not be resolved through foreign intervention, but a Syria-Syria approach and added that both Iran and the US should help implement this.
Victim of chemical weapons
The President himself says Iran will do its religious and humanitarian duty to send food and medicine. Rouhani made no mention of retaliation if Syria is attacked. He did mention the allegations of chemical weapons use, saying: "We completely and strongly condemn the use of chemical weapons because the Islamic republic of Iran is itself a victim of chemical weapons."
Former president and chairman of the Expediency Council, Ayatollah Hashemi Rafsanjani, in Tehran, added: "Unfortunately Syrians, who have been struggling for about two years with civil war, all kinds of suffering and extraordinary displacement are now also under foreign threats because of unproven allegations of chemical weapons use."
Meanwhile, Hossein Dehghan, Iran's new defence minister, ruled out sending troops or weapons to Syria: "The Syrian's do not need us to provide them with weapons because they have a defensive anti-aircraft system themselves."
The messages are not all the same however - Iran's Supreme Leader Ayatollah Seyyed Ali Khamenei said the US will suffer loss if it attacks.
He made the comments speaking to the Assembly of Experts in Tehran: "The objective of the recent commotion about Syria which has started on the pretext of chemical weapons is the same, but the Americans are trying to play with words and employ rhetoric to pretend that they have become involved in this case on humanitarian grounds… the Americans are making claims about humanitarian issues in spite of their past record in Guantanamo Bay and Abu Ghraib prison, their silence on the use of chemical weapons by Saddam Hussein in Halabja and on Iranian cities, and their killing of innocent people in Afghanistan, Pakistan and Iraq."
'Support until the end'
The hardest line has come from Qassem Soleimani, the head of Iran's elite Qods force unit, who said Iran will support Syria "until the end" in the face of any US strikes. "The aim of the US is not to protect human rights, but to destroy the front of resistance (against Israel).”
The front of resistance he refers to has Hezbollah at its centre. But he did not mention what kind of support "until the end" Iran would employ.
But a year ago, the head of Iran's Revolutionary Guards, Mohammad Ali Jafari, said members of the elite Qods force were in Syria but only to provide Assad's government with "counsel and advice".
It's difficult to read Iran's positioning - it ranges, as stated above, from the moderate to military. But that is the nature of Iran's power structure - different groups for different points.
What Iran is waiting for is the reaction from the other side - the US to see if military strikes eventuate, if the situation escalates. And if that happens, analysts argue, Iran will be pushed away from Rouhani's moderate messages into something else. And this "something else", is unknown.