We’ve long said that President Biden’s open border policy is deeply damaging to America, the nation he swore to defend against all enemies foreign and domestic. 

But now you don’t have to take our word for it. 

You can just ask Joe’s wave-them-in henchmen!

In the course of a Freedom-of-Information lawsuit by the indefatigable Center for Immigration Studies, Biden’s Customs and Border Protection has admitted that the administration’s “let illegal migrants fly around the country with no ID” policy is dangerous.

So dangerous, in fact, that even letting the public know the names of the 43 airports trafficked some 320,000 illegal entrants last year would “reveal operational vulnerabilities that could be exploited by bad actors.”

Turns out erasing our border, letting jumpers jet around the country and creating a taxpayer-funded app to let would-be migrants schedule their illegal crossings utterly undermines national security. 

Who’d a thunk it?  

And — more crucially — what evidence does the CBP have that these “bad actors” aren’t currently exploiting the “security vulnerabilities” Biden created?

It’s not like the cartels and transnational gangs like MS-13 can’t get reports back from migrants who’ve taken the flights on where they landed.

No: This is Team Biden again only keeping migrant flights secret from the American public, just as with the Westchester charters The Post has exposed.

Now, every rational person has long known what the CBP’s belatedly admitted. 

Solid borders are the sine qua non of national security (and indeed of nations themselves). 

So even if Biden had “only” let in the 320,000 who got on planes, it would be a disaster of historic proportions. 

That figure, for comparison, is larger than the population of most US state capitals. 

But it pales next to the full amount Biden’s let in: 7.2 million across the southern border, greater than the population of 36 states.

And the influxes show no signs of stopping. 

The resulting waves have crushed tiny border towns like Eagle Pass, Texas, almost to the breaking point. 

The arrivals have put massive fiscal pressure on cities and their human-services infrastructures as far away as New York, where migrant costs are expected on the most optimistic forecast possible to hit $10 billion over the next fiscal year. 

As gratifying as it is to see the feds squirmily admit the truth, it’s beyond obscene that this fact had to be pried from them by legal action. 

As it is that, under Biden, the agencies tasked with securing the border have become little more than concierge services for illegal immigrants. 

Until Open Borders Joe is gone, expect the chaos to continue.