No world leader confounds, and infuriates, Americans more than the Russian president, Vladimir Putin.
President George W Bush once famously declared he was able to "sense his (Putin's) soul" but that was in 2001. Seven years later, Putin invaded Georgia, and Bush felt lost.
When the morning after President Barack Obama warned Putin of costs of invading Ukraine, and the Russian president did just that — sending in troops, Americans erupted.
CNN analyst David Gergen, who has worked with four American presidents, called Putin "a thug" on air, and several times. Others called him a "bully", a "cold-warrior".
It's game time now. Here are a few from a long and growing list of what Americans are saying about the Russian president.
He is a thug: That came from Gergen, of course. And then several other experts. They argued that Putin recognises no rules and laws and does pretty much what he wants, a mean street-fighter. First Georgia, now Ukraine.
He is a KGB holdout: Putin was once in the KGB, the bad boys to the American good boys, the CIA. And once a spy, always a spy, who, it is being said, has surrounded himself with spies like himself who remain convinced the Cold War is not over yet. And that makes him a "cold-warrior" also.
He is delusional: German chancellor Angela Merkel started that one, asking the other day if Putin was "out of touch with reality". Former secretary of state Madeleine Albright picked it up on Tuesday and called the Russian president "delusional".
He is a hypocrite: In a widely cited oped in the New York Times last year, Putin grandly lectured the US and Obama against military intervention in other sovereign nations. And look what he just did himself. That oped popped up on a few TV news channels and websites on Tuesday.
He is a true Russian nationalist: One foreign policy expert called Putin, rather admiringly, a true Russian nationalist who has a grand vision for Russia. "In fact, he truly believes in Russian exceptionalism," said the expert.
He is a rational man: Several reports citing White House officials in the past two days suggest President Obama believes Putin is a rational person. And one who can be reasoned with. The two spoke for 90 minutes on phone on Saturday.
He is a US-hater: Well, Putin may have brought this one upon himself saying stuff like this: "I think they sit there across the pond in the US, sometimes it seems … they feel like they're in a lab and they're running all sorts of experiments on the rats." He either hates the US, or doesn't think much of it. Or, is he just as intrigued?
He is very smart, smarter than some US presidents: He outmaneuvered Bush in 2008 and now Obama.