"The fact is that we in Europe, in Germany, have given positive assessments to systems that deserved criticism," he told German public radio on Tuesday after returning from a trip to the Gulf states of Kuwait and Qatar.
He said Berlin had often judged countries stable "although we are now seeing that they were completely unstable due to corrupt leadership."
Wulff said it was important to look carefully at each individual country in the Arab world instead of lumping them into one basket. "We have to learn much more about this part of the world because it is in Europe's interest to do so," he said.
The president had praise for Qatar, whose emir he described as working toward a peaceful coexistence of religions and cultures. He said in Kuwait he was able to speak frankly about issues and meet with representatives of civil society groups.
"I think you can achieve a lot more through that than by trying to assess the situation from a desk somewhere," he said.
He had critical words for Muammar Qaddafi, saying the Libyan leader had lost legitimacy and, in fact, contact with reality.
"When violence against peaceful demonstrators is used, when police or soldiers shoot at peace-loving people, we need to cut off contact," he said. It was for that reason that during his trip Wulff did not go to Bahrain, whose leader has used force against pro-democracy demonstrators there.