Perhaps they were never likely to get along.
On one side -- the freemarketeer Czech president, a vocal critic of the EU and self-styled debunker of what he calls "global-warming myths."
On the other side -- the onetime leftist student radical turned Green European Parliament member.
So when Vaclav Klaus met Daniel Cohn-Bendit at Prague Castle, their exchange was, to say the least, "frank and open."
"I've brought you a flag," Cohn-Bendit began, according to a transcript of the early-December exchange released by Prague Castle.
That's because Klaus has made clear he doesn't want the EU's blue and yellow standard flying at the castle.
Cohn-Bendit, part of a European Parliament delegation, went on to say he wasn't interested in Klaus's opinions on the EU's Lisbon reform treaty.
Klaus replied, "No one has spoken to me in this style and tone in my six years here.... I thought these methods ended for us 18 years ago. I see I was wrong."
Klaus's supporters were outraged at the delegation's treatment of the president.
But others suggested Klaus should be more respectful, too -- among them, French President Nicolas Sarkozy, who told the European Parliament a couple of weeks later: "The president of the European Parliament should not be treated like this, Europe's symbols should not be treated like this, whatever people's political engagement. [This kind of behavior] doesn't exist and it should not exist."
The sparring continued, with Klaus telling Czech Television on December 24 that Sarkozy and politicians like him were actually "anti-European" for not respecting the continent's diversity of views.
As the country prepares to take on the EU Presidency, Klaus increasingly has been thrust into the international spotlight.
The feisty 67-year-old's opinions are often contrary to mainstream views. Klaus did not, for example, join in the Czech government's criticism of Russia over Moscow's summer war with Georgia. He's also a vocal opponent of the environmental movement, calling its proponents alarmists motivated more by ideology than science.
And he's a long-time critic of the European Union for what he sees as its tendency to chip away at the national sovereignty of its member states. "Vaclav Klaus is a person hardly anyone is indifferent about. He's not someone people have no opinion on," says Petr Drulak of Prague's Institute for International Relations.
Klaus is also a man who appears to enjoy taking on his opponents. "He's a person who enjoys intellectual discussions, he likes getting stuck in, and he performs relatively -- or maybe even extremely -- aggressively in these discussions," Drulak notes.
Klaus is an economist who spent study periods in Italy and the United States in the 1960s. He spent the 1970s and most of the 1980s at the Czechoslovak State Bank, before entering politics during 1989's Velvet Revolution that ended communist rule.
As finance minister of Czechoslovakia and then Czech prime minister, he presided over the country's split into the Czech and Slovak republics, as well as the reforms that would transform a centralized economy into one based on free markets.
He founded the right-of-center Civic Democratic Party (ODS) and remained its chairman until 2002, when he gave way to Mirek Topolanek, the current prime minister.
In 2003 he succeeded Vaclav Havel as president and was narrowly reelected earlier this year to the largely ceremonial -- though politically influential -- post.
Earlier this month, growing rifts with the ODS leadership -- mainly about the Lisbon Treaty, which Topolanek backs -- led to Klaus giving up his position as honorary ODS chairman.
Klaus vs. Europe
He also said he would welcome the formation of a new, Euroskeptic party on the Czech political scene.
Before his country joined the EU in 2004, Klaus said he feared it would dissolve like a sugar cube in a cup of coffee.
Speaking to RFE/RL last year, Klaus illustrated his point by recalling two cars he'd seen at a traffic light. One had an old Czech license plate, with "CZ" in large letters; the other, an EU plate, where the "CZ" sign was much smaller:
"The EU is trying to make the letters that symbolize our state as small as possible. You can't even tell from a distance if there's an NL for the Netherlands written on there, or an SK for Slovakia. You can't tell. You either need binoculars or you need to be driving right next to the car," Klaus said.
"This is a textbook example of the attempt to suppress, to rub out the basic entity that has formed the European continent and has given this continent its characteristic features," he added.
Now in Klaus's line of fire is the EU's Lisbon reform treaty, meant to streamline decision making in the EU, and which the Czechs have yet to ratify.
He presented arguments to the Czech Constitutional Court when it held a hearing on the document last month. The court ruled the treaty was in line with the Czech Constitution and the pact is expected to go to parliament in February, where it is expected to be approved.
But Klaus says he will decide whether to sign the treaty only if Ireland -- which voted against Lisbon in a referendum -- changes its mind in another vote expected by late 2009.
It has all led to worries Klaus could overshadow the Czechs' six-month EU Presidency. But that, Drulak says, largely depends on the government.
"The Czech system is slightly unusual to the extent that the president doesn't have much in the way of powers or authority, but he's always an extraordinarily strong political personality. It's true of Klaus and it was for Havel and in the First Republic [after Czechoslovakia's founding in 1918], with Presidents [Tomas] Masaryk and [Edvard] Benes, they never had much [formal] authority but they were strong personalities," Drulak says.
"So how the real actual political process looks like depends on how well the government is able to stake out the president's territory, and say, 'You can be on this area, but not here,'" he continues. "That's what it will be like in the Czech EU presidency; whether the main voice is Klaus's or that of Topolanek's government will really be up to the government."
To paraphrase a recent article in the "Irish Examiner" newspaper about the Czech president, "Expect less sugar, and more spice, in the new year."