The U.S. and Russian militaries have both talked for years about "hybrid warfare" as the future of war. Yet it remains a fuzzy term with no fixed meaning. The general idea is waging unconventional war on multiple fronts and well beyond the traditional battlefield.

What's clear is the U.S. and its allies are doing this now — perhaps on a scale never seen before — as they attempt to counter Russia in the war in Ukraine.

Here's a look at what it means in the current conflict:

Q. How did "hybrid warfare" enter the military vocabulary?

The first prominent figure to talk about it publicly was James Mattis, the retired Marine Corps general and former U.S. defense secretary. He used the term in a 2005 speech, though he didn't go into detail.

Then in 2013, the Russian military's chief of the general staff, Gen. Valery Gerasimov, gave a speech on hybrid warfare that caught the attention of some Western journalists.

Gerasimov, it turns out, was not talking about a new Russian military doctrine. He was actually addressing what he believed the U.S. was doing to support uprisings around the world. Gerasimov speculated on how Russia might respond but wasn't proposing a new Russian approach.

But in 2014, Russia stealthily seized Ukraine's Crimean Peninsula using disinformation, cyberattacks and "little green men" in unmarked military uniforms. There was virtually no fighting. Some in the West described this as an example of the "Gerasimov doctrine," though there has never been evidence that such a game plan exists.

Mark Galeotti, a British journalist who closely follows the Russian military, wrote a mea culpa in 2018 titled "I'm Sorry for Creating the 'Gerasimov Doctrine.' "

"To my immense chagrin," he wrote, "I coined the term 'Gerasimov doctrine,' though even then I noted in the text that this term was nothing more than 'a placeholder,' and 'it certainly isn't a doctrine.'"

Q. How exactly are the U.S. and its allies waging this type of warfare?

The U.S. and its NATO allies haven't sent a single soldier into Ukraine, but they began their unconventional warfare before the first shot was fired.

The U.S. released intelligence in advance of the Russian invasion, "pre-bunking" Russian disinformation such as the claim that Ukraine is being run by Nazis.

President Biden's administration worked closely with Europe for months to ensure they would roll out a tough, unified sanctions package as soon as the war began.

The comprehensive sanctions continue to mount by the day. The U.S. on Tuesday announced sanctions against 11 Russian military leaders. The European Union and Japan both announced they were placing additional sanctions on Russian oligarchs.

One of the most important steps has been the U.S. sanctions on the Central Bank of Russia. This will keep President Vladimir Putin's government from getting access to roughly half of the $600 billion war chest it had amassed before the war.

Russia faces a cascade of bond payments that are due, starting Wednesday. If Russia defaults on any of these payments — considered a real possibility in the near future — it could become a pariah on international financial markets for years to come.

Q. These moves are being made at the government level. What else are we seeing?

On social media, the West is generating wave after wave of public support. Every day, sympathetic scenes of Ukrainian civilians are going viral.

Contrast this with Putin's crackdown on all forms of media, the arrests of thousands of protesters and swift punishment for those who stray from the Kremlin's version of the events in Ukraine.

"What we're seeing now is Russia failing dramatically at implementing its hybrid war objectives," said Dmitri Alperovitch, a Russia expert who heads the think tank Silverado Policy Accelerator. "In fact, they're prosecuting a conventional war on the ground in Ukraine and not doing a good job of it. They're just getting completely destroyed in the information sphere, with Ukrainians being much more adept at pushing their narratives globally."

In another major development, many iconic Western companies have already announced they are suspending operations or pulling out of Russia altogether. They include McDonald's, Apple, Starbucks, big airlines, big banks and big oil. Before the war, it was far from clear they would respond this way.

"Most of the impact is actually coming from Western companies that are unilaterally deciding to pull out of Russia," said Alperovitch. "They're not getting their marching orders from the CIA or the White House. They're doing this on their own. This is what the Russians truly underestimated. They thought that this would be all driven top down, and it's actually bottom up."

Q. Hybrid warfare may be widespread, but can it determine the outcome of the war?

The punishment for Russia is real. The country has been largely cut off from the world overnight. Russians are waiting in line at banks for hours to get money. The ruble has crashed; interest rates have doubled to 20%; the stock market is closed for a third week.

Collectively, this may be an unprecedented global pressure campaign against Russia.

But the single most important factor is still likely to be what happens on the ground between the Russian and Ukrainian forces. Ukraine has put up strong resistance, but Russia has the advantage in sheer firepower, allowing it to grind down Ukraine's defenses over time.

"We have to determine how we change Putin's calculus," said Alperovitch. "I think that can only come with economic pressure — turning Russia into a new North Korea, completely isolated economically and diplomatically. Putin's all in now, so it's very difficult to actually get him to change course."

Greg Myre is a national security correspondent for NPR who was based in Russia from 1996 to 1999. Follow him on Twitter: @gregmyre1.

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