The recent U.S defence agreement with Fiji may not be groundbreaking—Washington has signed similar deals with allies around the world—but it carries strategic weight.

According to Jennifer Parker, an expert at the National Security College, it signals that Fiji will likely see more U.S military presence, such as troop rotations, joint exercises, and coastguard missions.

“It’s a clear sign that we’ll likely see more U.S troops rotating through or visiting Fiji for exercises or for coastguard deployments,” she said.

But that doesn’t mean the U.S will establish a permanent military base in Fiji, as it has in allied countries like the Philippines and Japan.

U.S Secretary of Defence Lloyd Austin old journalists there was “o notion” of a permanent base, and the idea wasn’t on the table during talks.

“We did not have any discussions like that,” he said.

So why is the United States suddenly so intent on stepping up its efforts in Fiji, and why now?

One big reason is Fiji’s location.

Parker calls Fiji “really strategically important” because it sits on or near many of the vast maritime routes between Pacific ports used by warships and merchant vessels alike.

“If you think about the protection of sea lines of communication across the Pacific, access to Fiji is pretty central to that,” she said.

For decades the United States hasn’t been anxious about that access because it exercised overwhelming naval superiority across the Pacific.

That’s now changing. U.S defence planners know that China has now built a formidable navy capable of challenging U.S power in the region.

Beijing has also worked assiduously to cultivate stronger security and commercial ties across the Pacific, and U.S leaders have publicly declared that China wants to leverage that to set up military bases across the region.

Parker said while access to sea lines was “not being contested at the moment”, the U.S is clearly “concerned” by China’s increasing influence and is trying to buttress its own position.

“This is about building greater U.S influence and greater U.S access in Fiji,” she tells the ABC.

It’s not just Fiji. Last year the Biden administration struck a sweeping defence cooperation agreement with Papua New Guinea, while promising to help the country modernise and develop its defence forces.

The U.S is also helping to redevelop the Lombrum Naval Base on Manus Island, although funding has been slow to flow.

Anna Powles from Massy University says rising tensions between the U.S and China in Asia are “driving” increasing U.S defence engagement across the Pacific.

“The U.S is seeking a series of security arrangements…to embed the bilateral relationship within the recipient country’s security eco-system and facilitate the U.S military’s ability to operate in the Pacific, including, for example, access to bases,” she tells the ABC.

She argues that if the U.S succeeds in that, it not only sends a “symbolic message” but will also help it project power through the Pacific.

“All these agreements provide the U.S Navy with options in the Pacific, both in peacetime and, particularly, during a potential crisis.”

If the United States is taking its first steps in Papua New Guinea and Fiji, it is moving with much greater speed and urgency in Pacific waters closer to China.

The military is racing to upgrade, restore and expand facilities across multiple U.S Pacific territories, as well as in independent Pacific states that have “Compact” agreements tying them closely to Washington.

U.S troops are clearing the jungle on Tinian Island in the Northern Marianas, restoring a vast World War II-era airfield not far from the major U.S military base in Guam.

They’ve already rebuilt another WWII airfield in Palau on the island of Peleliu – where the U.S and Japan fought a vicious and bloody battle in 1944 – and are installing advanced new radar systems in other parts of the country.

It’s a similar story on the island of Yap in the Federated States of Micronesia, where the U.S hopes to extend yet another old airfield.

Some details of the strategy might be classified but U.S planners and defence leaders are blunt about what they are doing, and why.

If war breaks out, the U.S expects China will strike military targets in what defence planners sometimes call the “first island chain” closest to the Chinese mainland – including American bases in Japan and the Philippines.

Both Guam and the Pacific Island bases that are being rapidly redeveloped are in what’s sometimes called the “second island chain” – within China’s reach, but harder and more taxing for it to strike.

And if China succeeds in destroying or disabling the U.S base in Guam, the military wants to be able to send its troops, warships, planes and critical supplies to other facilities across the second island chain, to make sure it can keep on fighting.

Parker says if a full-scale conflict breaks out between the U.S and China in Asia, then U.S Pacific territories and bases in Micronesia could quickly become “critical”.

“If there was to be a conflict in the Indo-Pacific it’s pretty clear that any U.S and allied forces in the first island chain would suffer significant losses and would need to be a fall back outside the first island chain,” she said.

“And the Pacific becomes critical in terms of being able to position and fight back, in a conflict scenario.”

The expanding latticework of defence and policing agreements across the Pacific also sits uncomfortably with the rhetoric used by its leaders, most of whom preach for peace and non-alignment.

For example, Fiji Prime Minister Sitiveni Rabuka, who stood beside the U.S defence secretary on Saturday, has been championing the idea of an “Ocean of Peace” in the Pacific.

Rabuka and other Pacific leaders – including those who have struck security arrangements with Beijing – seem confident they can square that circle, enjoying the benefits of security investments without risking being caught up in a regional conflagration or losing their sovereignty.

But Anna Powles says there is still a “tension” between the rhetoric used by Pacific leaders and the security agreements they are increasingly signing off on.

“There needs to be a wider conversation about what these potentially competing positions mean for Pacific countries and the region overall and what the obligations are of Pacific countries in a time of crisis,” she says.

Some civil society groups in the Pacific are also deeply uneasy about the way outside powers are trying to entrench their positions, saying it’s driving a rapid militarisation of the Pacific.

“Clearly there is an agenda that has been set,” says Sharon Bhagwan, a prominent Fijian activist working on peace and security issues.

“The question should be asked, should the investment really be about militarisation, when we need hospitals, when we need the human security agenda to be met?”

“Isn’t that far more important?”

She says Pacific governments and regional organisations need to invest real time and effort building a practical framework for the “Ocean of Peace” Rabuka has championed.

“There’s actually a very critical need right now to actually make sure that our governments, our intergovernmental agencies, particularly the Pacific Islands Forum, is actually getting better at peace building, rather than at militarisation,” she says.

But Parker says while Pacific leaders might face some “difficult” questions in an era of strategic competition, they’re also adept at exploiting it.

“In many ways for Pacific Island nations this period of competition could actually be a great opportunity to get greater investment, and much-needed resilience in some of their infrastructure,” she said.

“So certainly, it’s a difficult position to be in. But there are lots of opportunities as well,” said Bhagwan.