WASHINGTON — As NATO faces a resurgent Russian military, a substantial number of Europeans do not believe that their own countries should rush to defend an ally against attack, according to a comprehensive survey to be made public on Wednesday.

NATO’s charter states that an attack against one member should be considered an attack against all, but the survey points to the challenges the alliance faces in trying to maintain its cohesion in the face of an increasingly aggressive Russia.

“At least half of Germans, French and Italians say their country should not use military force to defend a NATO ally if attacked by Russia,” the Pew Research Center said it found in its survey, which is based on interviews in 10 nations.

Ivo H. Daalder, a former American ambassador to NATO and the president of the Chicago Council on Global Affairs, said that after a quarter-century in which NATO worried little about defending its territory against Russia, “it will take a serious effort by the alliance to convince its public of the need to prepare for, deter and, if necessary, respond to a Russian attack.”