GOLAN HEIGHTS - MAY 10: (ISRAEL OUT)  IIsraeli Iron Dome defence system, designed to intercept and destroy incoming short-range rockets and artillery shells, stands near the Syrian border on May 10, 2018 in the Israeli-annexed Golan Heights. Some 20 rockets were fired at Israeli military bases by Iranian forces from southern Syria just after midnight on Thursday, sparking the largest ever direct clash between Jerusalem and Tehran, with Israeli jets targeting numerous Iranian-controlled sites across Syria. On Monday  U.S. President Donald Trump pulled out of the Iran deal. (Photo by Lior Mizrahi/Getty Images)
Lior Mizrahi/Getty Images Europe/Getty Images
GOLAN HEIGHTS - MAY 10: (ISRAEL OUT) IIsraeli Iron Dome defence system, designed to intercept and destroy incoming short-range rockets and artillery shells, stands near the Syrian border on May 10, 2018 in the Israeli-annexed Golan Heights. Some 20 rockets were fired at Israeli military bases by Iranian forces from southern Syria just after midnight on Thursday, sparking the largest ever direct clash between Jerusalem and Tehran, with Israeli jets targeting numerous Iranian-controlled sites across Syria. On Monday U.S. President Donald Trump pulled out of the Iran deal. (Photo by Lior Mizrahi/Getty Images)
Now playing
01:34
Israel: Dozens of Iranian targets hit in Syria
Several were killed and injured when an unknown gunman opened fire on a military parade in the southern Iranian city of Ahvaz, Irans state television Press TV reported Saturday.
ISNA/ISNA
Several were killed and injured when an unknown gunman opened fire on a military parade in the southern Iranian city of Ahvaz, Irans state television Press TV reported Saturday.
Now playing
01:35
Video shows aftermath of Iran parade attack
File: Israeli troops patrol the Israeli-occupied sector of the Golan Heights on January 18, 2015.
File: Israeli troops patrol the Israeli-occupied sector of the Golan Heights on January 18, 2015.
Now playing
00:58
Israel: Iranian forces fire rockets at Golan Heights
An Iranian war-boat fires a missile during the "Velayat-90" navy exercises in the Strait of Hormuz in southern Iran on December 30, 2011. Iran, which has been carrying out war games in the Strait of Hormuz over the past week, has said that "not a drop of oil" would pass through the strait if Western governments follow through with planned additional sanctions over its nuclear programme.
 AFP PHOTO/IIPA/ALI MOHAMMADI (Photo credit should read ALI MOHAMMADI/AFP/Getty Images)
ALI MOHAMMADI/AFP/Getty Images
An Iranian war-boat fires a missile during the "Velayat-90" navy exercises in the Strait of Hormuz in southern Iran on December 30, 2011. Iran, which has been carrying out war games in the Strait of Hormuz over the past week, has said that "not a drop of oil" would pass through the strait if Western governments follow through with planned additional sanctions over its nuclear programme. AFP PHOTO/IIPA/ALI MOHAMMADI (Photo credit should read ALI MOHAMMADI/AFP/Getty Images)
Now playing
02:57
US: Major Iran naval exercises underway
An Iranian woman walks past a mural depicting the Statue of Liberty with a dead face, painted on the wall of the former US embassy in the capital Tehran on August 7, 2018 - US President Donald Trump warned countries against doing business with Iran today as he hailed the "most biting sanctions ever imposed", triggering a mix of anger, fear and defiance in Tehran. (Photo by ATTA KENARE / AFP)        (Photo credit should read ATTA KENARE/AFP/Getty Images)
ATTA KENARE/AFP/Getty Images
An Iranian woman walks past a mural depicting the Statue of Liberty with a dead face, painted on the wall of the former US embassy in the capital Tehran on August 7, 2018 - US President Donald Trump warned countries against doing business with Iran today as he hailed the "most biting sanctions ever imposed", triggering a mix of anger, fear and defiance in Tehran. (Photo by ATTA KENARE / AFP) (Photo credit should read ATTA KENARE/AFP/Getty Images)
Now playing
03:46
Iranians say they don't hate Americans
Iran sanctions impact ordinary families.
CNN
Iran sanctions impact ordinary families.
Now playing
02:08
How US sanctions hit ordinary people in Iran
Iranian women chant slogans during an anti-US demonstration outside the former US embassy headquarters in the capital Tehran on May 9, 2018. - Iranians reacted with a mix of sadness, resignation and defiance on May 9 to US President Donald Trump's withdrawal from the nuclear deal, with sharp divisions among officials on how best to respond.
For many, Trump's decision on Tuesday to pull out of the landmark nuclear deal marked the final death knell for the hope created when it was signed in 2015 that Iran might finally escape decades of isolation and US hostility. (Photo by ATTA KENARE / AFP)        (Photo credit should read ATTA KENARE/AFP/Getty Images)
ATTA KENARE/AFP/AFP/Getty Images
Iranian women chant slogans during an anti-US demonstration outside the former US embassy headquarters in the capital Tehran on May 9, 2018. - Iranians reacted with a mix of sadness, resignation and defiance on May 9 to US President Donald Trump's withdrawal from the nuclear deal, with sharp divisions among officials on how best to respond. For many, Trump's decision on Tuesday to pull out of the landmark nuclear deal marked the final death knell for the hope created when it was signed in 2015 that Iran might finally escape decades of isolation and US hostility. (Photo by ATTA KENARE / AFP) (Photo credit should read ATTA KENARE/AFP/Getty Images)
Now playing
01:39
How will US pulling out of deal impact Iranians?
Iranian lawmakers burn two pieces of papers representing the U.S. flag and the nuclear deal as they chant slogans against the U.S. at the parliament in Tehran, Iran, Wednesday, May 9, 2018. Iranian lawmakers have set a paper U.S. flag ablaze at parliament after President Donald Trump's nuclear deal pullout, shouting, "Death to America!". President Donald Trump withdrew the U.S. from the deal on Tuesday and restored harsh sanctions against Iran. (AP Photo)
AP
Iranian lawmakers burn two pieces of papers representing the U.S. flag and the nuclear deal as they chant slogans against the U.S. at the parliament in Tehran, Iran, Wednesday, May 9, 2018. Iranian lawmakers have set a paper U.S. flag ablaze at parliament after President Donald Trump's nuclear deal pullout, shouting, "Death to America!". President Donald Trump withdrew the U.S. from the deal on Tuesday and restored harsh sanctions against Iran. (AP Photo)
Now playing
00:38
Watch: US flag set alight in Iran's parliament
Samin
Now playing
02:15
Risking it all by rejecting the hijab
My Stealthy Freedom and White Wednesdays
Now playing
01:32
Outrage after 'morality police' confront woman
An image grab taken from a handout video released by Iran's Mehr News agency reportedly shows a group of men pushing traffic barriers in a street in Tehran on December 30, 2017.
Ten people died overnight in fresh unrest in Iran, local media reported on January 1, 2018, despite President Hassan Rouhani calling for calm and vowing more "space for criticism" in a bid to head off days of protest. / AFP PHOTO / MEHR NEWS / Handout / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / HO / MEHR NEWS" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS 
NO RESALE - NO BBC PERSIAN / NO VOA PERSIAN / NO MANOTO TVHANDOUT/AFP/Getty Images
HANDOUT/MEHR NEWS/AFP/Getty Images
An image grab taken from a handout video released by Iran's Mehr News agency reportedly shows a group of men pushing traffic barriers in a street in Tehran on December 30, 2017. Ten people died overnight in fresh unrest in Iran, local media reported on January 1, 2018, despite President Hassan Rouhani calling for calm and vowing more "space for criticism" in a bid to head off days of protest. / AFP PHOTO / MEHR NEWS / Handout / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / HO / MEHR NEWS" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS NO RESALE - NO BBC PERSIAN / NO VOA PERSIAN / NO MANOTO TVHANDOUT/AFP/Getty Images
Now playing
01:32
Dashed hopes: Reasons Iran protests kicked off
Rod Rosenstein
pool
Rod Rosenstein
Now playing
01:39
DOJ: Iranians hacked US professors
AFP/Getty Images
Now playing
01:41
Protests turn violent in Iran
Iranian students protest at the University of Tehran during a demonstration driven by anger over economic problems, in the capital Tehran on December 30, 2017.
Students protested in a third day of demonstrations sparked by anger over Iran's economic problems, videos on social media showed, but were outnumbered by counter-demonstrators. / AFP PHOTO / STR        (Photo credit should read STR/AFP/Getty Images)
STR/AFP/AFP/Getty Images
Iranian students protest at the University of Tehran during a demonstration driven by anger over economic problems, in the capital Tehran on December 30, 2017. Students protested in a third day of demonstrations sparked by anger over Iran's economic problems, videos on social media showed, but were outnumbered by counter-demonstrators. / AFP PHOTO / STR (Photo credit should read STR/AFP/Getty Images)
Now playing
02:08
Iranian officials: 'Provocateurs' to be targeted
A demonstration at the University of Tehran on Saturday
STR/AFP/Getty Images
A demonstration at the University of Tehran on Saturday
Now playing
01:47
Protesters angry over economy, corruption
A still frame from a YouTube video published on Friday, December 29 purporting to show a protest in Mashhad, Iran. CNN cannot independently confirm its authenticity.
YOUTUBE
A still frame from a YouTube video published on Friday, December 29 purporting to show a protest in Mashhad, Iran. CNN cannot independently confirm its authenticity.
Now playing
01:45
Why are citizens protesting in Iran?
Getty Images
Now playing
02:15
Why are Iran and Saudi Arabia so at odds?
(CNN) —  

Israel says that it’s done with strikes on Iran – for now. France fears an escalation. Iran has its finger on the trigger. But, really, it’s Russian President Vladimir Putin who sits in the hot seat.

Where once the US would have been the brake on spikes in Syrian violence, there is a real possibility President Donald Trump’s withdrawal from the 2015 Iran nuclear deal is greasing the wheels towards a wider regional war.

In recent months, the world’s top diplomat, UN Secretary-General António Guterres, has warned that Israeli and Iranian tit-for-tat strikes in Syria could quickly boil over to a regional conflagration.

Overnight Wednesday, rockets fired by Iranian forces from inside Syria toward Israel triggered a forewarned robust response from Israel’s military – targeting Iranian military assets in Syria.

Since early February, when Israel says it shot down an Iranian drone laden with explosives that was launched from Syria, the Israel Defense Forces have increased retaliatory strikes in Syria at Iranian targets.

Some of those strikes are reported to have killed several Iranian fighters. Yet until this point there had been no Iranian retaliation.

The sudden surge in the exchange of rockets Wednesday night – on the heels of Trump’s exit from the Joint Comprehensive Plan of Action – hints that Iran has suspended its strategic restraint.

If so, the likelihood that the Iranian-Israeli confrontation will escalate increases.

In Tehran, President Hassan Rouhani warned Germany, France and the UK, that they have only “a very limited time to save the JCPOA.” But he is a moderate. The Iranians fighting in Syria fall under a more hardline command.

It’s their comrades who have been killed in Israeli strikes and their patience will have worn thinner than Rouhani’s strategic politicking.

Most European diplomats fear that once the Trump’s administration leans on European businesses hard enough, they won’t be able to plug the economic shortfall, something Rouhani needs so he can sell the Iran deal without America at home.

In short, the gloves in a potential Israel-Iran confrontation are coming off. The question is this: were Wednesday night’s strikes the opening salvo, or a sign of what is to come?

01:20 - Source: CNN
Israel and Iran trade rocket fire

President Emmanuel Macron of France fears the former. His staff in Paris say he is pushing for calm: “He calls for de-escalation and he will talk about this with the German Chancellor today.”

Israeli Defense Minister Avigdor Liberman said on Thursday morning that most of Iran’s infrastructure in Syria was hit and that he hopes this chapter of “Iranian radicalism” is over. But indicating that what happens next is down to Iran, he added: “If it will rain in Israel, there will be a biblical flood on the other side.”

In Damascus, a Greek reporter asked President Bashar al-Assad if Syria would be the venue for world war three. His response: “No, for one reason: because fortunately, you have a wise leadership in Russia.”

Putin – as many international diplomats have warned could happen – finds himself, absent a working peace plan in Syria, riding a tiger. A bigger war in Syria would require a bigger military spend from him – something that would further strain his own stretched economy.

Recently reelected, he has plenty of political capital but not a lot of real cash to spare. US and European sanctions have been eating a hole in Russia’s pocket. The ruble has had a rocky ride in recent months.

During his Wednesday visit to the Kremlin, Israeli Prime Minister Benjamin Netanyahu is understood to have warned Putin about strikes on Iran’s military assets inside Syria.

As Iran is Russia’s principal ally keeping Assad in power, Moscow is very carefully tracking Israel’s every move.

For whatever reason, Putin appeared willing to see Iran hit, knowing the straining and destabilizing effect it may have on their alliance backing Assad.

That Netanyahu, Trump’s most ardent supporter in dumping the JCPOA, was in Moscow the day before the attack signals many things – not least the dangerous complexity of having so many powers at play in such a confined conflict. But it also emphasizes the diminishing US influence in Syria – and the region in general.

In Riyadh on Wednesday, Saudi Arabian Foreign Minister Adel al-Jubeir reiterated his country’s warnings about Iran’s nuclear ambitions, saying: “We have made it very clear that if Iran acquires nuclear capability we will do everything we can to do the same.”

After Israel, the Saudis are the biggest backer of Trump’s decision to pull out of the JCPOA. They fears growing Iranian influence in the region – not just to their north in Syria and Iraq, but over their southern border in Yemen.

On Wednesday, Iranian-backed Houthi rebels, who tossed Yemen’s internationally recognized government from power four years ago, fired long-range ballistic missiles into Saudi. One was reportedly shot down by a US-made Saudi counter-missile battery just outside the capital Riyadh.

In recent months, Houthis have stepped up missile attacks targeting Riyadh. None have gotten through so far. But patience in Riyadh is running thin – the expectation there is that Trump’s exit from the JCPOA could signal a ramped-up Saudi targeting of Houthi leaders.

How Iran would handle its Houthi proxies in this case is unclear. But international concern has been growing, particularly over the past week, as the Saudi-led coalition’s airstrikes in Yemen have allegedly hit several civilian targets recently.

In pulling out of the Iran nuclear deal, Trump hinted at the peace benefit for the region: “If I allowed this deal to stand, there would soon be a nuclear arms race in the Middle East. Everyone would want their weapons ready by the time Iran had theirs.”

While no one expected those lofty long-term goals realized already, just two days later, most diplomats hoped the lid could be kept on tensions until everyone outside the White House could figure out the next step forward.

There was no “plan B.” It’s being made up on the fly, with no guarantees hardliners don’t derail the world’s diplomats.

Escape routes are still open, but the fog and consequences of sudden conflict may soon shut them down.

Today, it’s still possible – albeit highly improbable – that should Trump decide, he could give European businesses “cutouts” and allow them to continue working in Iran; then maybe Iran’s moderates can buy more time and rein in their hardliners before it’s too late.

But the reality is, exiting the JCPOA has ushered in a new era of international relations where the unexpected and unpredictable have a far greater possibility of rapidly outpacing common sense and routine diplomacy.