When you think of climate change, images such as melting glaciers, polar bears or intense cyclones often come to mind. You might even reflect on scientists coming to grips with complex data, or coal-fired power stations belching pollution.

One of the things least likely to enter your head is the U.S. military.

But the impact of climate change on our security is one of the gravest risks we face, which is why our men and women in uniform see it as such a high priority.

In military parlance, climate change is a "threat multiplier" -- a factor that can worsen existing scarcities and tensions, and amplify the risk of instability and conflict, affecting whole nations and regions.

U.S. military analysis of this threat stretches beyond our own borders to include concerns about the security consequences for our allies and partners in geostrategically significant parts of the world, including Asia-Pacific.

Japan, for example, is one of our closest allies in the region, and despite its thriving economy and society, it is uniquely exposed to the security risks of climate change. According to two recent studies I participated in, published by the Center for Climate and Security, Japan is ill-prepared for these risks, and is potentially increasing climate change-related security risks to itself and its interests.

Southeast Asia is a case in point.

Southeast Asia's vulnerable coastal megacities, propensity for natural disasters and high rates of migration and forced displacement leave its social and political systems exposed to climate change shocks and stresses. Climate-related disruptions in these markets, when they inevitably come, will reverberate throughout their trading partners.

Japan should be worried. And it should prepare.

Southeast Asia has long been a favoured location for low-cost, high-quality supply chains, making it increasingly attractive for domestic market consumption of top tier Japanese goods and an important contributor to Japanese corporate profitability and general economic well-being.

Japanese carmakers, for instance, dominate the five main Southeast Asian markets, with 84 percent market share and numbers in excess of 2.6 million vehicles sold in 2016.

And it's not just exports.

One of the aforementioned reports by the Center for Climate and Security, Japanese Industry in an Unstable Climate, examines exposure of Japanese business to climate-related security challenges in Southeast Asia. It reveals that 17 percent of Japan's imports are from countries that are vulnerable to climate security risks. Despite this, only 27 percent of Japanese companies have business continuity plans for natural disasters in the region, while almost 80 percent have no measures to cope with flooding. Our friends in the Japanese business community are potentially sleepwalking into disaster.

A companion report, Climate Change Lessons from the U.S. Military, argues that the U.S. military and key Japanese industries, as two global enterprises, share similar exposure to the security risks of climate change in Asia-Pacific and beyond. It calls on Japan to heed the lessons and actions of the U.S. Department of Defense for recognizing and reducing the security risks of climate change.

Unfortunately at the moment, current policies and investment decisions may exacerbate the climate change-driven security risks that plague the U.S. military and Japanese industries alike.

For example, expenditures of public money from the likes of the Japan Bank of International Cooperation and Nippon Export and Investment Insurance to finance coal-fired power plants in Indonesia, Vietnam and Myanmar -- engineered by Japanese companies -- lock in years of carbon pollution that will contribute to the acceleration of climate-related security risks in the region. This is happening as many development banks and lending institutions globally are stepping back from financing coal -- including three Singapore banks in the last few weeks.

To mitigate this problem, all companies investing in Southeast Asia -- including Japanese companies -- should consider the total cost of ownership of climate change. This includes both physical risks and the capacity of the relevant governments to respond, and rebuild, while maintaining political and economic security.

In order to bring down the likely scale and scope of security risks to Japanese interests in the region, and the mutual interests of the U.S.-Japanese alliance, including those of our respective militaries, coal investments also need to halt and make way for smart, clean energy solutions.

One of the primary maxims of war is to know your enemy. A common enemy of our time is climate change. And it is an enemy we and our Japanese allies are not taking seriously enough.

This is not a successful strategy.

There is still time to change and prepare, but it is running out fast.

(Dennis McGinn is a retired vice admiral of the U.S. Navy and a Senior Member of the Advisory Board, the Center for Climate and Security. He is a member of the Center for Climate and Security Advisory Board, and Senior Member of the Executive Committee Member at the International Military Council on Climate and Security.)