In the wake of President Donald Trump’s decision to withdraw the United States from the historic Paris Climate Agreement, governors, mayors, businesses, and people across the country have declared that they still support the agreement. They know that this decision not only represents a fundamental abdication of U.S. leadership on the global stage, but also generates concrete consequences for generations to come in terms of national security, economic prosperity, and diplomatic credibility.

Choosing not to take action against climate change will put our troops in harm’s way more often in the not-so-distant future. Here’s why: The Pentagon has long acknowledged climate change as a “threat multiplier” because its effects make the work of our men and women in uniform around the world even more difficult than it already is. More frequent and severe storms and droughts—and their consequences, including resource shortages and mass migration—mean the U.S. military will be asked take on more humanitarian relief missions, there will be stronger extremist groups on the battlefield, and possibly worse. These aren’t fringe views. Defense Secretary Jim Mattis made the argument himself in his confirmation hearing testimony.

Fighting climate change isn’t about declaring war on the weather; it means taking steps to use clean energy and shoring up societies already under the threat of constant disaster. For this reason—operational realities rather than political preferences—climate change mitigation policies have been a priority of the U.S. military for years.

Looking backwards to old sources of energy and letting opportunities for innovation pass us by will hurt our economy, too. As Trump remains fixated on the shrinking number of coal jobs in Appalachia—a product of market forces, not over-regulation—clean energy jobs continue to surge at home and around the world. Growth in the solar industry is outpacing broader job growth in the United States (with a large number of veterans in particular entering the field), and Forbes described ‘wind turbine technician’ as one of the fastest growing jobs in the country.

Contrary to some claims, choosing clean energy isn’t about punishing people who worked on the energy infrastructure that powered American supremacy in the 19th and 20th centuries. Just as investment, innovation, and export in fossil fuel-related technology gave us the edge then, so should solar, wind, and other clean energy in the coming decades. Unfortunately, we were already behind China and India in clean energy production, and the European Union and China announced a plan for clean energy partnership as soon as Trump abandoned the Paris Agreement.

And finally, even though it may seem abstract now, the damage that Trump’s withdrawal from Paris has done to America’s credibility abroad will prove significant. Prime Minister Justin Trudeau of Canada tweeted his disappointment in the “federal government of the United States,” and French President Emmanuel Macron delivered a speech, in English, directed at the U.S. population regarding climate change—both moves that liberal democracies tend to reserve for communicating to and about rogue states.

While the president and some of his advisors may view these warning signals that the United States is being left behind by the rest of the world as some kind of badge of honor, most Americans know better. The truth is that the consequences of this isolation will not stay confined to issues of climate action. We cooperate with other nations in areas like terrorism and trade—subjects that are relevant to the personal safety and pocketbooks of all Americans. Nations cannot be fickle, temperamental, and foolish in one area of conversation and expect to project consistency and strength in others.

The Paris Climate Agreement was meant as a jumping-off point for progressively more significant global action on a problem of historic proportions. It was American leadership that produced the agreement, bringing all of the more than 200 signatories to the table and pushing them towards personalized goals that could be reported upon and ratcheted up in the future. Now the White House has opted to turn away—setting the stage for real security, economic, and diplomatic consequences now and for years to come.

Clearly, Trump and his advisors have charted the wrong course. It will be up to the rest of us Americans in towns, companies, and households across the country to hedge against these serious consequences. In doing so, we will send a message to the rest of the world about our continued resolve to lead from the front on one of the most pressing challenges of our time.