They are a few tiny specks in the sea, but their potential impact is huge.
Satellite images released by The Asia Maritime Transparency Initiative in the United States appear to show China's artificial islands in the South China Sea with new military capabilities.
The recent analysis shows anti-aircraft guns and weapons defence systems visible on seven of the island structures.
Many lands claim territory in the South China Sea, including Vietnam, the Philippines, Taiwan, Malaysia and Brunei, but China says the area is its sovereign territory.
Now, it appears increasingly like it is willing to fight for it.
A specialist in Chinese and Asia-Pacific security from the Australian National University, Dr Amy King, says it puts Australia in a very uncertain position.
She says it could leave Australia wedged between its two most important international relationships.
"It creates real uncertainty, I think, about China's intentions for the South China Sea. So the development of these weapons systems, even if they're defensive, suggests that China envisages the possibility of a conflict in this region. And I think it's very important for Canberra to remember that the South China Sea dispute goes to the heart of the strategic relationship between the US and China."
On a visit to the United States last year, President Xi Jinping assured US president Barack Obama that China was not militarising the South China Sea.
The latest developments now have further strained their relationship.
Chinese foreign ministry spokesman Geng Shuang has told reporters in Beijing the United States needs to stay out of China's business in the region.
"We hope the United States can abide by its promises on not taking sides on the sovereignty dispute in the South China Sea, that they respect the efforts of countries in the region to maintain peace and stability and (they) do more to promote peace and stability in the South China Sea."
More than $6 trillion of trade passes through shipping lanes near the islands every year.
The United States sent a warship to the region in October, citing freedom-of-navigation laws, a move China deemed provocative.
The commander of the US Pacific command, Admiral Harry Harris, speaking in Sydney this week, has said the US maritime forces in the area are ready for action if provoked.
"The Indo-Asia-Pacific region is the most consequential region for America's future. This fact alone makes the US-Australia strategic alliance more important than ever before. We will cooperate where we can, but we will be ready to confront where we must."
Complicating the volatile state of affairs is what the new US president will decide to do once he is in power.
President-Elect Donald Trump sparked concern in China when he spoke directly to Taiwan's president and seemed to pivot away from the long-time US policy of One China.
The phone call ended decades of silence between the United States and Taiwan, which China sees as a breakaway province and not an independent country.
Dr King says the next move from the incoming US administration is unclear as all sides take an aggressive stance.
"Trump is very unpredictable right now. He's pivoting in all sorts of different directions. And I think it's in Australia's real concern that we have a president-elect who's threatening a global trade war with China. We face a really important moment of uncertainty, both towards China and towards the US."
