One in three Germans thinks a war could break out between Russia and NATO over the conflict in Ukraine, according to an opinion poll published on Wednesday, a finding that helps explain the country's cautious approach to the crisis.

Germans, whose country was devastated in World War II and split into East and West during the Cold War, have applauded Chancellor Angela Merkel's efforts to prevent an escalation of Russia-NATO tensions.

Germany long resisted U.S. calls for tougher sanctions against Russia over its annexation of Crimea, and shifted position only after the Malaysia Airlines Flight MH17 was downed over Ukraine.

On Wednesday, NATO said Russia may be poised to invade Ukraine, as it has amassed 20,000 combat-ready troops on Ukraine's eastern border.

In a Forsa Institute poll of 1,001 people published by the weekly magazine Stern, 33 percent said they would not exclude war as a result of the Ukraine crisis, while 62 percent said war was unlikely. Some 41 percent of women polled on July 30 and July 31 said war was possible while only 21 percent of the men surveyed agreed.

The European Union and the United States agreed further sanctions against Russia over last week.