China’s latest attempt to establish a beachhead in the Pacific Islands has run aground, to the relief of United States leaders wary of Beijing’s growing naval power.

“This is an important decision to reinforce sovereignty, transparency, and the rule of law,” Defense Secretary Mark Esper said Friday. “Many nations in the Pacific have discovered far too late that Chinese use of economic and military levers to expand their influence often is detrimental to them and their people.”

Esper issued that statement in a public celebration of a decision by the attorney general of the Solomon Islands, who invalidated a deal that would have given the state-owned China Sam Group control of an entire island for 75 years. U.S. and other Western analysts believe China is trying to establish a naval base in the Pacific theater that could be used to threaten U.S. forces and American allies.

“That potentially extends out China's operating sphere to the inner rings of a key U.S. ally like Australia,” Patrick Buchan, a former Australian Defense Ministry adviser at the Center for Strategic and International Studies, told the Washington Examiner. “Anywhere on the map you can control, you can operate forward from there.”

Those plans are on hold, as Solomon Islands Attorney General John Muria declared the 75-year lease “unlawful, unenforceable and must be terminated with immediate effect” on Thursday evening. Muria concluded that the deal had not been vetted in advance, as required by law, and that “it does not contain essential clauses of such obligations of both parties” such as confidentiality agreements and termination clauses.

“This is just a stall,” opposition lawmaker Peter Kenilorea said. “The fact that the contract itself is flawed doesn’t negate the intention behind the signing. The intention is still there."

China has targeted the Solomon Islands with a charm offensive in recent months. Beijing persuaded the Pacific Island nation to cut ties with Taiwan, the island refuge of the government overthrown when the Chinese Communist party came to power in 1949. Chinese President Xi Jinping hosted Solomon Islands Prime Minister Manasseh Sogavare for a state visit on Oct. 10, followed by last week’s revelation that a Chinese company had cut a deal to invest in the island of Tulagi.

“Everyone is really scared about the possibility of China turning the island into a military base,” Michael Salini, a local business owner, said last week. “That is what really scares people — because why else do they want to lease the whole island?”

A naval port in that part of the world could give China significant leverage in a crisis, according to American analysts, by empowering the Chinese military eventually to interfere with the U.S. Navy’s supply lines between Hawaii and Guam, a crucial American military outpost in the Indo-Pacific. U.S officials believe Chinese war planners are using “predatory” economic investments to gain the ability to block the U.S. military from key ports around the world.

“I’m concerned by the [Chinese Communist Party’s] efforts to expand its military footprint in the Indo-Pacific region,” Arkansas Sen. Tom Cotton, a Republican member of the Armed Services Committee, told the Washington Examiner earlier this week. "Pacific Island states are particularly vulnerable to China’s debt-trap diplomacy. The Administration has made significant strides over the past two years in collaborating with our Asian allies to offer these states financial alternatives to Beijing’s predatory lending.”

But the U.S. doesn’t have veto power over such agreements. “The key issue remains the level of concern and indeed anger among the populace of the Solomon Islands, ” Buchan said. “The leaders of the Solomon Islands have treated their own people like pawns on a chessboard.”