As I write these words, on the 16th anniversary of the Sept. 11 attacks, a major American city has been brought to its knees and over 7 million Americans have been told to evacuate a multi-state region. Mass damage is expected, and the governor of Florida has warned the population that “law enforcement cannot save you.”

If this had been caused by terrorists, we would recognize it for the national security threat that it is. But it was caused by hurricanes, so we argue.

But this is nonsense. Climate change is a national security issue. It takes American lives and destroys American cities. It hurts our economy and damages our national infrastructure. It threatens our energy production and interferes with our ability to project our power abroad. It creates global instability, which our enemies can take advantage of.

Climate change hurts America in every way a declared enemy would and must be recognized for the threat it is. The fact that the climate is a natural thing is irrelevant; germs are natural too, but we still have to protect ourselves against germ warfare.

To deny that climate change is occurring is the equivalent of saying that there is no terrorism; airports bomb themselves. The arguments about why it’s happening are only relevant insofar as they help us stop it. We have to recognize what threatens us. Houston and all of Florida — an entire state — were taken down by what is effectively a weaponized climate. That is a national security issue.

To say that we can’t create policies that address climate change because they’ll hurt the economy is like saying that we shouldn’t have a military because someone will have to pay for it. National defense costs money. We have to defend ourselves. Technology to reduce emissions is every bit as important as new weapons systems. Infrastructure built to resist extreme weather is every bit as important as army bases. They have become basic tools of national defense; they are not negotiable.

And we’re spending the money anyway — $15 billion has just been allotted for cleanup in disaster relief so far, and you can expect more to follow.

If terrorists were to bomb an American city and do only a fraction of the damage done, we would respond vigorously with new policies and a national mobilization. That is, in fact, what happened after Sept. 11, 2001.

We need to recognize the destruction in Houston and Florida for what they are — a new Pearl Harbor. Defending America means addressing climate change.

Benjamin Wachs archives his work at Email him