On a Pacific archipelago 2,400 miles southwest of Hawaii, the United States’ enormous military capability collides with the accelerating climate risk that threatens to erode it.

Kwajalein Atoll in the Marshall Islands is home to the Ronald Reagan Test Site, a state-of-the-art installation for space surveillance and the fulcrum for American missile defense systems to thwart attacks on the homeland. If North Korea launched an intercontinental missile, the radar at Kwajalein would track it so that missiles based in Alaska could try to intercept the weapon before its nuclear warheads reached the United States.

In a little over a decade, climate change could make the installation and other military sites on Kwajalein uninhabitable. A 2018 study commissioned by the Pentagon found that even before anticipated sea level rise swallows Kwajalein, ocean waves could wash over the low-lying islands often enough by 2030 to harm underground drinking water sources and the multibillion-dollar military infrastructure.

The challenges at Kwajalein offer a glimpse into how the damage and looming risks from climate change have become a soft underbelly of military readiness.

In a new series, Dangers Without Borders, InsideClimate News examines how climate change is affecting the military’s ability to protect national security at this moment of global insecurity. Russia and China are pursuing provocative agendas from the South China Sea to the Arctic as President Donald Trump equivocates about America’s traditional alliances. According to a recent bipartisan expert report to Congress, the U.S. military has been so weakened in recent years that it now runs the risk of losing a war to China or Russia.

One of the most tangible effects of climate change on the U.S. military can be seen after extreme weather batters its equipment and installations, calling into question whether military units can be deployed quickly and effectively if conflicts were to flare.

In October, Hurricane Michael slammed Tyndall Air Force Base near Panama City, Florida, inflicting what officials called “widespread catastrophic damage.” The year prior, the Pentagon spent $1.3 billion to repair bases and equipment damaged by Hurricanes Harvey, Irma and Maria. In 2014, flash floods ravaged the critical combat training grounds at Fort Irwin, California, requiring $65 million in repairs.

A recent Pentagon survey at 3,500 military installations found that half of them already face destabilizing weather, including droughts, extreme heat, wildfires, high winds and inland flooding, and many are grappling with multiple threats.

[Read U.S. Soldiers Falling Ill, Dying in the Heat as Climate Warms]

Fragile Global Security: Watching for the Next Syria

Even as climate change starts to threaten military bases and infrastructure, it simultaneously worsens tensions abroad that could draw in American forces. National security officials have described global warming as a threat multiplier—the extra stress from a drought or typhoon that could push an already weak foreign land into chaos and send gusts of mass migration or terrorism through regions and even continents.

“When I look at climate change, it’s in the category of sources of conflict around the world and things we have to respond to,” Gen. Joe Dunford, chairman of the Joint Chiefs of Staff, said during a talk at Duke University in November. “In fact, I can’t think of a year since I’ve been on active duty that we haven’t conducted at least one operation in the Pacific along those lines due to extreme weather in the Pacific. And then, when you look at source of conflict—shortages of water, and those kind of things—those are all sources of conflict.”

In a 2015 report to Congress, the Pentagon pointed to the Syrian civil war as an example of how climate change can aggravate the fragility of a nation already riddled with tensions and poor governance. At the time of the Arab Spring in 2010, Syria was already under great stress. The authoritarian regime of Bashar al-Assad was unpopular, and an influx of more than one million Iraqi refugees strained basic services.

At the same time, the worst drought in 500 years had shriveled large swaths of rural Syria, a country long plagued by water scarcity. Thousands of Syrians moved from farms into towns and cities. The migration contributed to the instability, which erupted into popular uprisings and, eventually, a cataclysmic civil war. Hundreds of thousands of people died and waves of refugees moved through the Middle East and into Europe and shook the political order as far as Germany. Today, more than 2,000 U.S. troops are fighting in Syria and northern Iraq, with the end of American involvement still unclear.

National security experts who understand how climate change moves a nation from bad to worse are asking, where is the next Syria? Will desertification in parts of Africa rob people of their farms and make some of them susceptible to the call of extremist groups? Will Pakistan’s habitually beleaguered government be able to take care of its people if catastrophic flooding strikes, as it did in 2010, when American troops responded? And will the U.S. military, if called upon, be able to respond to international crises if climate change has hammered its ships, planes and training grounds?

“We are going to be caught flat-footed because we are not systematically asking, ‘what if?’” said Alice Hill, a National Security Council official under President Barack Obama who ran a team focused on global risks. “Climate change is not the sole risk or the primary risk, but it’s a constant risk, and it’s on a trajectory to accelerate. If we don’t consider this in decision making, we are leaving ourselves ill-prepared.”

Researchers are looking into how drought and higher temperatures fueled by climate change might be exacerbating internal migration, and with it poverty and violence, in Honduras, Guatemala and Nicaragua, where thousands of people are fleeing as they walk to Mexico and the United States. The migration has become a political flashpoint in the U.S., and now a military question. President Trump has already sent 5,600 troops to the southern border to meet the migrants.

Amid Trump’s Denial, Pentagon Is an Island of Climate Action

The intertwined challenges of fragile global security, American military readiness and climate change take on heightened urgency in the Trump era. In a recent poll, nearly three-quarters of Americans said they believe the world has grown more dangerous during the Trump administration. Polls of Western European allies show a widespread lack of confidence in Trump, especially compared to Obama. Several countries critical to national security interests lack an American ambassador, including Egypt, Pakistan, Saudi Arabia, Turkey and Mexico.

At the same time, the White House denies mainstream climate science, halted work across federal agencies on climate change, and pulled the country out of the Paris climate accord as part of the broader collapse of American climate diplomacy. Trump rescinded an executive order that called in part for supplying the national intelligence community with the latest climate science, an Obama-era directive meant to help analysts better monitor the impact of warming on potential global hotspots. He also stripped mention of climate change as a threat to global security in his first National Security Strategy document issued in late 2017.

Still, the Pentagon remains a rare island of climate action within the administration, in part because Defense Secretary James Mattis and other top officials have publicly stated that global warming is real and a danger to national security and global stability. Service members at all levels and branches have seen the effects of climate change, and climate denial does not seem widespread in the ranks, veterans and analysts said. Congress also has given the Pentagon some cover, mandating that it identify by the end of 2018 the 10 military installations at greatest risk of damage from climate change.

But the military’s efforts to address climate change are patchwork, and no one knows how effective the constellation of disjointed initiatives might be, veteran officers and other national security experts said.

Some former Obama administration officials contend that, for all its rhetoric, their administration also didn’t provide the money needed to improve climate resilience—especially at critical military installations.

To launch this series, InsideClimate News is examining the impact of rising seas at one such facility, the Norfolk Naval Shipyard in Virginia.

[Read U.S. Nuclear Fleet’s Dry Docks Threatened by Storms and Rising Seas]

Like Kwajalein atoll, it is essential to national security. The shipyard is one of the few sites where the Navy can maintain and repair its fleet of nuclear-powered submarines and aircraft carriers, among the military’s most strategically important assets.

The carefully coordinated maintenance schedules of the ships often have them opened up and exposed for months and even years at a time in a dry dock. There, they are increasingly vulnerable to coastal flooding from surging seas and extreme weather. An inundation could disable or destroy the vessels or the yard, and consequently, reduce the American presence on the world’s oceans. Read this story, and watch our animation bring this threat to life. And stay tuned as we explore other pressing climate security issues with in-depth stories and multimedia.

Top image: Photo illustration based by an image by Robert Nickelsberg/Getty Images of Marines responding after Hurricane Sandy.