President Trump might have the occasional spat with Prime Minister Malcolm Turnbull, but he's lucky that Australia remains such a steadfast and valuable U.S. ally.

We gained new evidence of this truth on Monday, when Australia participated in a counter-smuggling naval exercise alongside the U.S. and South Korea.

Yet these exercises are just the tip of the iceberg. Unlike many U.S. allies, Australia has pledged to spend 2 percent of GDP on defense by 2020-2021 and has undertaken a major procurement program to boost its military. Last month, Australia announced that its newest class of frigates will adopt the Aegis ballistic missile tracking and defense system. By also purchasing F-35 fighter jets, electronic warfare and maritime surveillance aircraft, and advanced submarines, Australia will soon attain top tier power projection capability.

And these expensive purchases aren't about creating jobs. Instead, they reflect Australia's commitment to assist the U.S. in restraining Chinese military hegemony in the Pacific.

The need is real. Though the North Korean nuclear crisis has distracted the world's attention, China is building an empire of economic blackmail in the Asia-Pacific. Establishing island fortresses deep in the East and South China Seas, China is implicitly warning nations like Vietnam, Malaysia and the Philippines to bow to its political orders or face a militarily enforced trade embargo.

Seeking to preserve the rule of law and free commerce that allows trillions of dollars in annual trade flows through these waters, the U.S. has rightly sought to deter China's efforts. Unfortunately, we're having to do so without much help from our U.S. allies.

Australia's procurement choices prove that's about to change.

After all, while the Australian military won't be able to match the scale of U.S. military forces, its defense investment program is designed to supplement the U.S. military in fleet defense (Aegis), enemy detection (maritime surveillance) and precision striking capabilities (submarines, F-35s, and electronic warfare aircraft). All these things would be crucial in any maritime conflict with China.

This Australian effort should not be taken for granted.

With China employing various means to draw American allies into its corner, Australia could easily follow the British and French example and ignore Chinese island imperialism in return for lucrative business deals. Or, for example, Australia could keep its defense spending below 2 percent and claim its support for the "Five Eyes" intelligence alliance is sacrifice enough.

Fortunately, Prime Minister Turnbull sees the long game. While he'll likely have left office before most of the new military equipment is deployable, Turnbull recognizes that Australia's future prosperity and international stability depend on standing alongside America.

For his strategic foresight and stout friendship, Turnbull deserves American thanks.