But the United States might be getting a lot less than it asked for.
Since Saudi Arabia's announcement on December 16, questions have been raised about the coalition's membership, its commitment to fighting terror and its overall purpose.
Many see the move as aimed at bolstering Saudi prestige and countering Iran more than forming an effective fighting unit. And some critics suggest that Riyadh is acting less as the result of American leadership and more because of an American vacuum in the region.
"This event is not seeking to work with the U.S. but is an independent Saudi effort to bolster one of its crucial efforts: to be the leader of the Islamic world," said Saudi Arabia expert Simon Henderson of the Washington Institute for Near East Policy.
And it's far from clear just what the contours of that effort are.
The Saudis have announced that the coalition will have a headquarters in its capital of Riyadh, but have not detailed when that headquarters will be set up, the amount of forces each nation will contribute or how they would put those forces to work, Henderson told CNN.
In fact, specifics related to the coalition are so scarce that some of the nations listed as members, including Lebanon, reportedly said they didn't know of their own involvement until after the announcement.
Lack of details on coalition
Saudi Arabia hands said the lack of information detailing how this coalition will organize or carry out any military action indicates the move is most likely a symbolic bid to reaffirm Saudi leadership in the region rather than a serious plan to go after terrorists.
"Frankly, until I see evidence that proves otherwise, I assume it means ... nothing," said David Weinberg, a senior fellow at the Foundation for Defense of Democracies, adding that it is difficult to take the announcement seriously when the Saudis have introduced similar initiatives in the past and not delivered on them.
Specifically, the Saudis have not yet followed through on significant counterterrorism commitments they made last year in signing the Jeddah Communique with the U.S. and other Arab nations, said Weinberg, a former Democratic staff member on the House Foreign Affairs Committee.
The communiqué called for, among other things, stopping the flow of financing to ISIS, repudiating ISIS' ideology, aiding humanitarian relief and contributing to the reconstruction of communities devastated by ISIS.
When pressed last week on the specifics of how the new anti-extremist coalition would operate, including whether it would include ground forces, Saudi Deputy Crown Prince and Defense Minister Mohammed bin Salman answered: "Nothing is off the table."
In an equally vague response on how the group of nations plans to combat radical groups, Saudi Foreign Minister Adel al-Jubeir said, "The decisions will be made by individual countries in terms of what to contribute, and when to contribute it, and in what form and shape they would like to make that contribution."
In addition to Saudi Arabia, the coalition is said to include Bahrain, Bangladesh, Benin, Chad, Comoros, Ivory Coast, Djibouti, Egypt, Gabon, Guinea, Jordan, Kuwait, Lebanon, Libya, Malaysia, Maldives, Mali, Mauritania, Morocco, Niger, Nigeria, the Palestinian Authority, Pakistan, Qatar, Turkey, Togo, Tunisia, Senegal, Sierra Leone, Somalia, Sudan, the United Arab Emirates and Yemen.
It is no surprise that Saudi Arabia, a Sunni state, did not include Shiite-led Iran, Iraq and Syria in the group, but Weinberg said the omission of several other Sunni countries, including Oman, which works with the Saudis as part of the Gulf Cooperation Council, raises questions about whether the Saudis have the ability to effectively influence other nations in the region to take action.
The grouping of mostly Sunni-led nations also leads some observers to believe that this coalition is an effort by the Saudis to shift focus to countering Iran, the longtime enemy of Saudi Arabia, while the U.S. has zeroed in on the fight against ISIS.
"Obama has made the reintegration of Iran, on some international issues, a major goal of his presidency. But many states in the region, specifically Saudi Arabia, want to cut out Iran," said Michael Rubin, a former Pentagon official during George W. Bush's administration. Sunni states like Saudi Arabia "see Iran as the greater threat."
Their concerns intensified after the U.S. signed a deal with Iran in July that would limit Tehran's nuclear ability in exchange for lifting several international oil and financial sanctions -- a move many Sunni states see as paving the way for rapprochement between Tehran and Washington.
Though the Obama administration has denied having such grand ambitions, it has been willing for the first time to include Iran in talks on ending the Syrian civil war -- whose chaos ISIS thrives on -- and looking for other places where Iran can help defeat the Sunni terror group.
Then there is the issue of just what "terrorism" the Saudi coalition would fight -- which could complicate any cooperative efforts with the U.S.-led group already bombing ISIS in Iraq and Syria. For one thing, several Sunni states want to go after groups beyond ISIS that are also a threat to their governments, while the U.S. sees ISIS as the organization to target.
"As long as (the Saudi coalition) is fairly meaningless, they don't need to define terrorism," Henderson said. "But if the U.S. and Europe are going to try to help the Saudis create something more solid, they are going to have come up with a terrorism definition, and that is going to be a challenge."
The Saudis are not necessarily obvious candidates for defining or combating terrorism, given their own ideological leanings, according to the former senior adviser for countering violent extremism in the Obama State Department, William McCants.
The fact that ISIS uses Saudi state text books in its schools shows that the Sunni radical group shares ideological similarities with the hardline Saudi state religion even if they differ over their political visions, said McCants, now a fellow at the Brookings Institution's Center for Middle East Policy.
Despite the Saudis' open condemnation of "Islamic extremism" and stated desire to form a coalition to fight it, they are "not serious about going after any links between their own state ideology and affinities with these groups," he said.
According to Henderson, the Saudis also fundamentally believe that "there is no such thing as jihadi terrorism" because "terrorism isn't in fact a Muslim behavior."
This mindset differs greatly from those in the West who are part of a conversation about terrorism that "regards the character of Islam as an important part of why there is a problem," Henderson said.
The spectrum of what is and is not considered terrorism also varies among nations said to be included in the newly formed coalition, especially those with larger Shiite populations, like Bahrain and Lebanon.
Even if the members of this new coalition are able to come to a consensus on which groups qualify as terrorists, former officials and experts said the likelihood of it becoming the Muslim-led military force that President Barack Obama and other Western leaders have been calling on to send ground troops into Iraq and Syria and to fight ISIS is unlikely.
Saudi Arabia and several other members of the new coalition are also technically part of the U.S.-led group already striking ISIS and offering assistance to local forces, but their involvement in that campaign appears to already be drawing down.
Saudi Arabia and the United Arab Emirates are down to about one mission against ISIS targets each month, a U.S. official told CNN on last week. Bahrain stopped participating in the autumn.
The U.S. and its Western partners continue to say the ground war against groups like ISIS needs to be fought by Muslim troops on the ground. But, according to Henderson, "this (new Saudi) declaration fails to fill the gap which the U.S. has been looking for in terms of a Muslim military alliance, which would be the best political way to go after ISIS."
"My fear is, big picture, is that this will merely be a fig (leaf)," he added.
However, the U.S. maintains for now that the Saudi-led coalition is in line with what it has been asking of its allies in the region.
"It represents an effort to coalesce those states against terrorist threats to include ISIS and that is what we've been wanting to see, an intensification by everybody against this threat," State Department spokesman John Kirby said on the day the coalition was announced, adding that "there is still a lot more" the administration needs to know about it.
Gulf states seek greater U.S. action
At the same time, Gulf states, particularly Saudi Arabia and the UAE, have also been asking the U.S. to take steps of its own, namely to broaden the mandate of fighting terrorism to combat extremism in all its forms rather than only ISIS.
Arab diplomats have long warned that if the U.S. didn't take on this wider array of threats, their countries would. An early example was the decision by Egypt and the UAE to strike armed Islamist factions in Tripoli, Libya, independently of the United States in August 2014. It's the kind of military effort that might be undertaken by the new coalition should it begin to act.
In the eyes of Rubin, the former Pentagon official, the creation of the Saudi coalition sends a signal to the Obama administration that the U.S. has abandoned the playing field in the Middle East.
"No one expects these states to do anything but issue declarations, but you have to take it as symbolically important," Rubin said.
The move signifies that the Saudis still want to be a major influencer in the region, especially at a time where the sense is that the sectarian crisis is nearing a tipping point and that the U.S. won't necessarily keep that crisis in check, he said.
Rubin, now with the American Enterprise Institute, said there are no signs that the Saudis coordinated their coalition with the U.S., and that such a surprise move would itself be an indication of the diminished role of the U.S. in the region and the Obama administration's loss of credibility on the world stage.
He called it a "symbolic slap in the face."
But McCants, the former State Department official, defended the administration and said the Saudis were stepping up in response to U.S. and Western pressure that they do more.
The Saudis may "feel they have some responsibility to bear for ideology affinities between its state religion and ISIS," he said.
Either way, Weinberg said the Saudi move could in the end help U.S. goals even if that was not its intention or capability at present.
"The U.S. wants to see Saudis muster military power under the U.S. umbrella of what they are doing," Weinberg said.
Since the Saudis have put themselves forward as a leader on this issue, he said, it might make it easier for the U.S. "to make them put their money where their mouth is."