When Leon Panetta, the former US defence secretary, addressed an audience of diplomats and foreign policy enthusiasts earlier this week in Abu Dhabi, he was eager to praise America's relationship with Gulf countries.
Even as Mr Panetta was paying tribute to those deepening ties, they were in evidence.
Mr Panetta's successor, Chuck Hagel, was touring the Middle East to wrap up a US$10 billion (Dh36.7bn) arms deal to Saudi Arabia, the UAE and Israel that is aimed, he said, at sending "a very clear signal" to Tehran that the military option remains on the table over its nuclear programme.
On the other side the Atlantic, the emir of Qatar held talks in Washington yesterday with the US president, Barack Obama, a week after White House visits by the Crown Prince of Abu Dhabi, Sheikh Mohammed bin Zayed, and the Saudi foreign minister.
While relations between Washington and the countries of the Gulf Cooperation Council (GCC) are strong, Mr Panetta was quick to add on Monday evening that they are evolving.
Caught in a domestic budget crisis and balancing countless commitments across the globe, the US is increasingly looking to its allies in the Gulf to share the work of securing the Arabian Gulf.
"It is our hope that the Gulf Cooperation Council, the GCC, can play an important role in the future providing security for this region," he told an audience at the Emirates Centre for Strategic Studies Research.
Across the board, he said, Washington is urging allies to build local capacity.
"That's what we're doing for the UAE and that's what we're doing with other countries. Yes, we give them the help they need, we give them assistance, but the fact is that they have to help provide for their security."
For months, many commentators from Riyadh to Doha to Manama have sensed and relayed this shift in US policy.
In interviews, many analysts and current and former policymakers insist that changes are not occurring at the expense of the Gulf countries. If anything, they say, Washington views the GCC as a stable partner in a region roiling with change.
Yet the perception of wavering US attention persists and is not without some basis in reality, one US expert said.
Since the fall of the shah of Iran in 1979, US warships and aircraft have become a routine presence in the Arabian Gulf, guarding shipping lanes and keeping Tehran in check. Now, the military seems to be moving in the opposition direction.
"We've withdrawn totally from Iraq. We are in the process from withdrawing from Afghanistan. We have substantially curtailed our naval presence in the Middle East. And the US president has announced a foreign-policy pivot to Asia," said Christopher Harmer, a former deputy director of future operations at the US Navy's Fifth Fleet, based in Manama.
"Those are four actions that say to the GCC that, whatever the situation, you have to deal with it without a lot of help with America," Mr Harmer said.
From the vantage point of the member nations of the GCC, Washington's military posture towards Iran has also undergone a shift.
In early February, Washington announced that it was withdrawing one of its two aircraft carriers from the Arabian Gulf, citing the high cost of maintaining the vessel.
Meanwhile, some naval strategists have suggesting publicly that Washington consider relocating the home port for the Fifth Fleet, which is currently Manama. At the moment, it is not a mainstream view, but it still has some traction, Mr Harmer said.
Taken together, these developments are viewed with alarm by some Gulf analysts, for whom no amount of reassurance from Washington of the importance of its partnerships in the Gulf seems enough.
"We keep hearing from Washington … that America is not leaving the Middle East," Abdulkhaleq Abdulla, a professor of political science at Emirates University, told American officials at a security conference in Manama in December.
"The fact that you keep saying this is an indication, in fact, that America is leaving the Middle East. The reality tells that America is no longer as involved and acting as a leader in Middle East issues," Professor Abdulla said.
To one prominent regional observer, it looks like estrangement.
"The GCC states and the United States look as if they are growing apart on an almost daily basis," Gulf Research Centre chairman Dr Abdulaziz Sager wrote recently in the Saudi daily Arab News.
"This is because on basically every issue of strategic importance and concern at the moment, the two sides are taking or have taken different positions."
The dismay about the changing US posture in the region dates back to 2011, when the Obama administration withdrew its support for Egypt's president at the time, Hosni Mubarak.
The move sent shock waves through the Gulf and the US response to the civil war in Syria has intensified concerns about Washington's loyalty to long-time allies in the region.
While Saudi Arabia and Qatar are widely reported to be supplying arms to the rebels seeking to overthrow President Bashar Al Assad, the Obama administration has been wary, worried that advanced weaponry may fall into the hands of extremist insurgent factions.
Underlying differences over Egypt and Syria is another disagreement, said Simon Henderson, fellow at the Washington Institute for Near East Policy.
"The fundamental difference between US and GCC is ostensibly over the Arab Spring. The GCC has this view that Iran is the problem," Mr Henderson said.
. The effect of a shift in the balance of power between Iran and the Gulf "appears to be underestimated in Washington", Mr Sager wrote.
"It is not clear whether the GCC states can continue to rely on US policy to not only protect the region but to also move it towards a more stable future."
Amid these differences of opinion and perception, there is no question that Washington would like to lean more heavily on its allies in the GCC to ensure regional security.
Before being named secretary of state, then-senator John Kerry commissioned a report on the US-GCC relationship that called for "increased burden-sharing as GCC partners contribute to their own regional security and stability".
Thus, the Obama administration and US Congress have approved countless weapons deals to the region in recent months, most notably the $10bn package set to be finalised this week, which would boost the missile and air force weapons systems available to the UAE and Saudi Arabia. That deal comes on the heels of one signed in 2011, in which Saudi Arabia purchased fighter jets worth $29.4bn.
Some analysts point out that burden-sharing is a sign that the relationship is growing, not under duress.
"I don't see any see any signs of rifts," said Saleh Al Khathlan, head of the political science department at King Saud University in Riyadh. "We do have disagreements now and then but we don't see anything that is different this time."
Mr Panetta said that one key to the future of American-Gulf cooperation would rest on better defence coordination among Gulf countries themselves. GCC countries "have to work together", he said.
Mr Harmer agrees that strategic interests will keep the alliance together at least for the moment. But tensions may only grow more pronounced.
"Fundamentally, because the US needs the GCC, the relationship is strong."