For years they have sought to get inside Mr Putin’s mind, to better understand his intentions.
With Russian troops seemingly bogged down in Ukraine, the need to do so has become all the more necessary as they try to work out how he will react under pressure.
Understanding his state of mind will be vital to avoid escalating the crisis into even more dangerous territory.
There has been speculation that Russia’s leader was ill, but many analysts believe he has actually become isolated and closed off to any alternative views.
His isolation has been evident in pictures of his meetings, such as when he met President Emmanuel Macron, the pair at far ends of a long table. It was also evident in Mr Putin’s meeting with his own national security team on the eve of war.
Mr Putin’s initial military plan looked like something devised by a KGB officer, one Western intelligence official explains.
It had been created, they say, by a tight “conspiratorial cabal” with an emphasis on secrecy. But the result was chaos. Russian military commanders were not ready and some soldiers went over the border without knowing what they were doing.
Single decision maker
Western spies, through sources they will not discuss, knew more about those plans than many inside Russia’s leadership. But now they face a new challenge – understanding what Russia’s leader will do next. And that is not easy.
“The challenge of understanding the Kremlin’s moves is that Putin is the single decision-maker in Moscow,” explains John Sipher, who formerly ran the CIA’s Russia operations. And even though his views are often made clear through public statements, knowing how he will act on them is difficult intelligence challenge.
“It is extremely hard in a system as well protected as Russia to have good intelligence on what’s happening inside the head of the leader especially when so many of his own people do not know what is going on,” Sir John Sawers, a former head of Britain’s MI6, told the Media.