Of all the priorities for US Secretary of State Antony Blinken on his fourth visit to the Middle East in three months, there is one message above all others that he wants to deliver.

His main mission on this trip is to ensure the Israel-Gaza war does not spread into a regional conflict.

As he flies between destinations in southwest Asia - a packed schedule that includes stops in Turkey, Jordan, Qatar, the UAE, Saudi Arabia and Israel - there is ample evidence, however, that the cauldron of tensions in the region is on the verge of boiling over.

Houthi rebels in Yemen have launched repeated missile and drone attacks on civilian shipping in the Red Sea, bringing traffic through that key international waterway to a near halt.

The US has warned that it will defend its interests. If the rebels persist, and the disruption to global commerce continues, an American military response may be inevitable - a development that would unnerve some key American Arab allies.

"We never see a military action as a resolution," said the Qatari prime minister in a joint press conference with Mr Blinken in Doha on Sunday. Sheikh Mohammed bin Abdulrahman Al-Thani said his biggest worry was that such action would "keep us in a loop that will never end and will create a real tension in the entire region".

On Saturday, Hezbollah forces in southern Lebanon fired a barrage of rocket attacks on northern Israel in reprisal for what appeared to be an Israeli-planned bomb attack that killed a key Hamas leader in Beirut. Israel responded with air strikes targeting Hezbollah forces in Lebanon.

An escalation there, Mr Blinken said later that day, was a "real concern". He called on regional powers with influence over Hezbollah - in other words Iran and, to a lesser extent, Turkey - to use their influence to "try to keep things in check".

That may be difficult. As the Washington Post reported, American officials are concerned that Israel may be considering a more expansive offensive against Hezbollah.

"We prefer the path of an agreed-upon diplomatic settlement, but we are getting close to the point where the hourglass will turn over," Israeli Defence Minister Yoav Gallant said on Friday.

Meanwhile, US military installations have been hit by rocket and drone attacks from militants in Iraq and Syria, where more than 3,000 American soldiers are stationed. In late October, a drone breached US defences and struck a barracks but did not detonate, according to a Reuters report, narrowly avoiding what might have been significant American casualties.

The US has responded with military action, including an air strike in Baghdad last week that killed Mushtaq Taleb al-Saidi, an Iran-backed militia leader.

Each of these episodes, taken individually, presents a threat to regional stability. When viewed as a whole, it suggests a Middle East teetering on the brink of wider war.

In Qatar on Sunday, Mr Blinken said the US has a plan to address the growing instability - and it hinges on winding down the Israeli military campaign in Gaza and working with Arab nations and the Israelis to establish a "durable" peace for the Palestinians.

"The United States has a vision for how to get there, a regional approach that delivers lasting security for Israel and a state for the Palestinian people," he said. "And my takeaway from the discussions so far ... is that our partners are willing to have these difficult conversations and to make hard decisions."

Therein lies the rub. After meeting with Saudi Crown Prince Mohammed bin Salman on Monday, Mr Blinken said he's seen a willingness to help stabilise and revitalise a post-war Gaza among all the leaders he's spoken with so far. But the US has to get Israel on board.

The timing of Mr Blinken's latest Middle East trip may give hints of the American strategy in this latest round of shuttle diplomacy. His early visits to Turkey and Arab nations before two days in Israel have allowed the secretary to take the temperature of regional players before sitting down with Prime Minister Benjamin Netanyahu and the Israeli War Cabinet.

Then the ball, as Americans like to say, is in the Israeli court.

"I'll have an opportunity to share with Israeli leaders everything I've heard thus far on this trip," he said on Monday. "I'm convinced that there is a future path that can actually bring lasting peace and security for Israel."

Behind all this is an American gamble - that resolving, or at least winding down, the Gaza War will cool tensions throughout the region. It is a bet that the various mini-crises - in the Red Sea, in Lebanon, and in Iraq and Syria - have not taken on a momentum of their own.

There is no peace in the region without a legitimate, peaceful solution to the Palestinian conflict, the Qatari prime minister said on Sunday. The question is, will there be peace with such a resolution?

During his November trip to the Middle East, Mr Blinken told reporters gathered on the tarmac in Ankara, Turkey, that countries across the region do not want war - and are working to prevent the conflict from spreading.

"Sometimes the absence of something bad happening may not be the most obvious evidence of progress, but it is," the US secretary said.

Since then, there has been ample evidence that while a wider war may not be wanted, the prospects for one has increased - despite the stated intentions and efforts of Mr Blinken and the Americans.