Putin aggressively has used information warfare, spreading disinformation and propaganda through social media. He's successfully used hacking and espionage to steal and then publish internal documents of political parties in the US and other target countries. He's used these tools to manipulate elections abroad.
He's waged diaspora warfare, stirring up Russian-speaking populations in countries abroad to create a pretext for Russian involvement in, for instance, Georgia and Ukraine.
He's pioneered cyber war, shutting down the electricity grids of Georgia and Ukraine, before dispatching military forces against them. He's used shadow armies, former Russian soldiers and serving troops on leave, to send the so-called "little green men" to conduct armed operations in Ukraine.
It was exactly these Russians out of uniform and their supporters who shot down MH17 over Ukraine in 2014, killing 298 civilians, including 28 Australians. Despite all evidence, Putin has never acknowledged any Russian involvement. And Russia has employed deniable assassination abroad of people judged to be traitors to the motherland, most recently Sergei Skripal.
This program of political war has been underway for a decade and accelerating. Yet in the face of tremendous volumes of evidence, the US and its European allies in NATO have been remarkably obdurate in accepting this reality.
Even the public declaration by the US intelligence community in January last year that it had "high confidence" that Russia had intervened in the US elections of 2016 failed to persuade many Americans, notably Trump and the 40 million Americans who still support him.
How could that be so? Partly it's because the US generally had come to hold Russia in low regard, almost contempt, after its empire, the Soviet Union, collapsed in 1991. The idea that Russia was powerful and capable seemed far-fetched.
Partly it's because Trump and his bloc admire Putin as a strongman role model. Trump wanted to identify himself with Putin, not against him. It seemed personally and politically inconvenient for Trump to admit the truth.
Partly it was a simple failure to recognise the nature of Russia's undeclared war. Reveron and Howard write that the "conventional military paradigm may be too powerful" to allow the US and NATO allies to see the paradigm of unconventional political war.
Which is very strange. Because the US successfully waged a holistic political warfare of its own for decades. The famed US diplomat George Kennan set out the strategy in a memo 70 years ago. It was titled "The inauguration of political warfare".
Kennan's 1948 memo expressed his admiration of Russian prowess, already evident to him: "The Kremlin's conduct of political warfare has become the most refined and effective of any in history," describing it as Lenin's synthesis of Marxist political theory with Clausewitz's theory of military strategy.
"We have been handicapped however by a popular attachment to a basic difference between peace and war, by a tendency to view war as a sort of sporting contest outside of all political context", and by "a reluctance to recognise the realities of international relations - the perpetual rhythm" of competition between states for power.
He might well have been writing in 2018 rather than 1948. Kennan urged the US to match the Russian effort: "We cannot afford to leave unmobilised our resources for covert political warfare." America, of course, responded to the challenge and ultimately triumphed in the Cold War.
But all of that seems to have been forgotten in today's America and has had to be painfully re-learned. Trump at the weekend finally confronted the reality of Putin's foreign policy. He pointed out that Putin was supporting the Syrian butcher, whom Trump called "Animal Assad".
And his administration is now imposing new economic sanctions on Russia for aiding and abetting Assad's chemical weapons attacks against his own people in the Syrian civil war.
Putin never forgot. The "breakup of the Soviet Union was the greatest geopolitical catastrophe of the 20th century," Putin has said. He has set himself the task of redeeming as much as possible from that catastrophe and he has revived the Russian political warfare manual.
A lifetime student of Russia, ANU professor emeritus and former head of Australia's defence strategy, Paul Dibb, says that "American intelligence agencies have all seen the evidence of Russian interference," and they understood what was under way. "Now even Donald Trump" by linking Putin to Assad seems to begin to grasp the situation.
Says Dibb: "Putin is a hard man leading a hard country and those who wrote them off after 1991 are fools. The question is, now that he's coming under attack, how hard will he hit back?"
Part of the answer was provided when a barrage of internet "dirty tricks" hit Britain and US. But it remains an open question. The political war is now, it seems, joined.
Or so it seemed on Monday. The US ambassador to the UN, Nikki Haley, had said the US Treasury Secretary, Steven Mnuchin, was about to announce new economic sanctions on Russia. But on Tuesday (Australian time) the Washington Post reported that Trump had "put the brakes on new Russian sanctions".
The Kremlin had complained that the planned US sanctions would amount to "international economic raiding".
Trump then "conferred with his national security advisers" the Post reported, "and told them he was upset the sanctions were being officially rolled out because he was not yet comfortable executing them, according to several people familiar with the plan".
The curious reluctance of Trump to confront Russia means that Putin can continue his political warfare against the US with impunity.
Peter Hartcher is the Herald's international editor.
Peter Hartcher is the political editor and international editor of The Sydney Morning Herald. He is a Gold Walkley award winner, a former foreign correspondent in Tokyo and Washington, and a visiting fellow at the Lowy Institute for International Policy.