(CNN) US President Donald Trump's recent decisions to avoid military action against Iran in the face of tactical humiliation and strategic threats have been smart, subtle and ethically unimpeachable.

They're also a gamble.

According to intelligence sources in the Middle East and the West, recent attacks on Saudi oil facilities were launched from Iranian soil. Iran has been blamed by the US, UK, France and Germany among others for being behind the cruise missile attacks; claims that the Houthi rebels in Yemen were responsible were dismissed as implausible.

But the outright allegation that the Iranians actually attacked Saudi Arabia from Iran -- an act of war -- has yet to be made in public, even though, according to the sources, intelligence officials have told politicians they are 100% certain their information is accurate.

The choice to hold such data back rests in the hope that, while it remains an open secret, there might be opportunities to dial down the dangers of war in the Gulf through diplomacy.

The extent of the urgency of achieving this was visible at the United Nations General Assembly last week where the French led efforts to lead the US and Iran towards talks.

Acknowledging a brazen act of violence against a sovereign nation would almost inevitably demand a violent response from that nation or her allies and put an end to diplomacy.

The gamble for Trump and other leaders is that a reluctance to act, in retaliation for what was a strategically effective attack on Saudi Arabia, may be seen in Tehran as weakness.

And that could result in a further escalation which, in the view of many sources in diplomacy and intelligence across the region, would most certainly trigger a conflict.

Attacking Iran would set off a complex war that simply could not be won by the West and its allies -- and could easily be lost.

However much the Iranians deny their involvement, it seems their actions hae been carefully calibrated to signal greater dangers to come -- and Iran's military reach.

Iranian military trucks carry surface-to-air missiles during a parade on Army Day, in Tehran in April 2017.

Iran raising the stakes

Imagine, now, a retaliation -- perhaps for another attack that (even accidentally) causes casualties.

A coalition led by the US would want to calibrate its response. Retaliation would have to be painful for the Iranians. But suggest a taste of worse to come.

Obvious targets would include the command and control structures of the Revolutionary Guard Corps (IRGC), air defenses around the country, weapons storage facilities and strategic communications hubs.

Elements of the nuclear program in Iran would be singled out, but they're largely in a semi-mothballed state anyway.

The Iranians know this. Anyone planning to attack Iran knows that they know this, and so genuine targets would be hard to find.

Iran will have studied international air campaigns against Saddam Hussein's Iraq, as well as those against Yugoslavia, Kosovo and Libya. The IRGC and the al Quds Force, its elite overseas wing, will have buried what matters most in mountains and set up decoys.

Iran has been raising the stakes steadily this year as economic sanctions imposed by the US bite hard into its economy. It has been angered by the apparent failure of the European Union and others to circumvent the US sanctions.

The US pulled out of the Joint Comprehensive Plan of Action (JCPOA), agreed with Iran in 2015, which limit its nuclear program in return for lifting sanctions last year.

Trump and other hawks, notably Israel's Benjamin Netanyahu, argued that the deal was "terrible." Additionally, they say Iran had dangerously squandered the economic benefits it enjoyed on destabilizing operations, often through proxies in Syria and Yemen.

They also say that Iran has continued to back Hamas in Gaza, and Hezbollah in Lebanon, while developing missile technology that has now been used to spectacular effect.

The US, and privately a number of allies, now want the whole thing renegotiated to put an end to Iran's missile program and its nuclear ambitions.

Iran says it is willing to resume talks but only if sanctions are lifted.

It is the danger of making war against Iran now that has so raised the specter of even greater horrors if a conflict is postponed.

But any attack on Iran could go from a show of force by the West, to all-out conflagration in moments.

Trump and other hawks say Iran has continued to back Hamas in Gaza, and Hezbollah militants (pictured) in Lebanon.

Iran's military reach

Hundreds of thousands of Shia militia in Iraq see Iran as their spiritual home. There are US bases all over Iraq next door to Shia militia camps where troops battle-hardened by the fight against ISIS could be turned against their American neighbors.

Thousands of Iranian troops as well as Iranian-commanded militia from Iraq and Afghanistan are currently fighting alongside Bashar al-Assad's forces in Syria.

Intelligence officials have been concerned that some, or all, of them as well as Syrian forces may be sent to try to recapture the Israeli-held Golan Heights the moment a war began with the US.

In southern Lebanon, Hezbollah, the Israelis believe, have at least 130,000 missiles pointed their way. Some of them are capable of hitting Tel Aviv and other locations further south already threatened daily by Hamas missiles from Gaza, where Iran supports the militant group.

Israel, America's most beloved ally in the Middle East, could immediately be sucked into a war with its neighbors that the Jewish State has frequently pointed out would be catastrophic, especially for Lebanon -- where there are 200,000 descendants of Palestinians who fled during and after the 1948 Arab Israeli war -- and following the 1967 Six Day war and subsequent occupation.

War in its neighborhood could threaten the Jordanian monarchy if the Palestinians there rise in solidarity with their brethren in Lebanon and Gaza. That's if the Iranian backed militias there attacked Israel and Israel responded with the devastating attack it has promised in defense.

Jordan has a peace treaty with Israel and is a strong US ally. There are an estimated 500,000 refugees in camps in Jordan -- descendants of Palestinians who also fled the 1948 and 1967 wars.

Palestinian refugees pose to be photographed in a Beirut refugee camp in 1973.

Meanwhile, in the Gulf there is anxiety over potential conflict with Iran amid concern that Iran may up the ante with more strikes against Gulf targets as a means to force negotiations back to the table.

"The conversation should no longer be about the JCPOA but Iran's missile program and its regional behavior which are as important if not more important. They have the potential to hold the region to ransom," a senior Gulf official told CNN.

Iran may already be at that stage.

In a conflict sparked by retaliation for what that same official called Iran's "nefarious actions," the Gulf is immediately vulnerable to rocket attacks.

One or two hits, or even hints of hits, on Dubai's airport, and its tourist industry would go into free fall.

Abu Dhabi has the lion's share of the Emirates oil -- but like Dubai it sits within range of conventional Iranian artillery, let alone sophisticated missiles.

Saudi Arabia, Kuwait, Bahrain, the UAE, Qatar: all export their oil and gas through the bottleneck of the Stait of Hormuz. Iran has, according to the US and UK, already demonstrated its ability to mine supertankers sailing through the choke point -- a complete strangulation of the world's most important oil seaway would be relatively straightforward.

A handful of cruise missiles that intelligence sources have told CNN were made in Iran damaged Saudi Arabia's oil industry so badly that panic-buying briefly set in on the crude markets, raising the price of oil by 20% for a short period.

Shutting off Hormuz, more strikes on the UAE and Saudi Arabia, as well as a brief uptick in oil prices could see crude rocket to $100 or $150 a barrel.

Iran's agenda is clear: to signal that it can cripple shipping in the Persian Gulf using mines placed on supertankers, in operations it denies.

And let's not forget the Hezbollah cells and Iranian intelligence operatives seeded around the world. Poised to strike at enemy (American or Israeli) targets wherever they present themselves.

The very reasons that hawks in the Trump administration wanted to hamstring Iran and get out of the nuclear agreement are those that make attacking it so dangerous.

It may be up to Trump and his allies to show some diplomatic subtlety. Negotiations are now urgent or Iran might indeed bring the house down.

Editor's note: This story has been updated. In 1948, Israel repelled invading Arab armies which attacked immediately after Israel declared its independence. In 1967, Israel launched a pre-emptive attack against what Israeli leaders believed were imminent attacks and invasions from neighboring Arab states. In both wars, Israel expanded its territory, some of which it has withdrawn from, some of which it has annexed, some of which it occupies to this day.