Behold a world without policing

For years, "broken windows" policing — the idea that the best way to prevent serious crime was to enforce laws against petty crime — was derided by critics as unnecessary, unjust, even racist. So cities across America pulled back from prosecuting the supposedly small stuff, like shoplifting.

Now we've seen a jump in violent crime.

Criminologists can debate the causes of the new crime wave. But many people intuitively understand that places in which decay and disorder become the norm are places where crime tends to thrive. That's because crime is largely a function of environmental cues — of the palpable sense that nobody cares, nobody is in charge, and anything goes.

We now live in a broken-windows world. I would argue that it began a decade ago, when then-President Barack Obama called on Americans to turn a chapter on a decade of war and "focus on nation-building here at home," which became a theme of his re-election campaign.

It looked like a good bet at the time. Osama bin Laden had just been killed. The surge in Iraq had stabilized the country and decimated al-Qaida there. The Taliban were on the defensive. Relations with Russia had been "reset." China was still under the technocratic leadership of Hu Jintao. The Arab Spring, eagerly embraced by Obama as "a chance to pursue the world as it should be," seemed to many to portend a more hopeful future for the Middle East (though some of us were less sanguine).

Review some of what's happened since then.

We vacated Iraq in 2011. But instead of getting peace, we got the horror of ISIS, forcing us to send back troops and fight a war that has lasted for years, cost thousands of civilian lives and led to the displacement of more than 3 million people.

Unrestrained violence in Syria forced millions into exile, bringing unbearable strain on countries like Lebanon while flooding Europe with refugees in 2015. One result was a populist backlash that included Brexit, big electoral gains for neo-fascist parties in France and Germany and a major assist to Donald Trump's presidential campaign.

China last year unilaterally revoked the "one country, two systems" policy for Hong Kong. Does anyone outside that city even remember?

Vladimir Putin seized Crimea in 2014, six months after the Syrian chemical-weapons crisis, and was met by a muted response. Putin fomented a pro-Russian insurrection in eastern Ukraine and was met by a muted response. Putin sent armed forces to support Assad in Syria and was met by a muted response. Putin interfered in our elections and was met by a muted response.

More recently, President Joe Biden has offered tough talk on Putin. But when it came to blocking Russia's Nord Stream 2 gas pipeline to Germany, his administration offered a muted response.

It's in this global context that the catastrophe in Afghanistan is playing out. Beyond the humanitarian calamity it represents for the Afghan people, the political debacle it represents for Biden (though he scarcely appears aware of it), and the national disgrace it represents for Americans who don't think we should go begging to the Taliban to extend our exit deadline, the Afghan surrender is the most visible evidence that the era of Pax Americana is over.

In this world, the temptation can only grow stronger for Putin to break the back of NATO by picking off a vulnerable member like Latvia (where one-quarter of the population is ethnically Russian and the opportunities for subversion are great). Ditto for China seizing Taiwan. For that matter, what keeps the Taliban (or some nominal offshoot that provides the Taliban with plausible deniability) from taking hundreds of stranded Westerners hostage and humiliating Biden just as Iranian revolutionaries once humiliated Jimmy Carter?

Some pundits lightly dismiss the notion of credibility in statecraft. But foreign policy is also conducted by taking the measure of your opponents, as John F. Kennedy learned after Nikita Khrushchev thrashed him at their summit in Vienna and built the Berlin Wall two months later.

If you're wondering why remote and godforsaken Afghanistan matters in places of allegedly greater strategic relevance to the U.S., ask yourself what signals this bungled withdrawal — the overconfident predictions, the lousy military intelligence, the incompetent diplomatic coordination, the unwillingness to stand by allies — sends about our capacity to deal with a more serious adversary, especially one that can hold the American heartland at risk.