Before the war in Iraq started, teacher Gary Tankard let his students at Bergen Catholic High School know where he stood, wearing a button that read, ''War is not the answer.'' Several of his colleagues did the same. Although Pope John Paul II was preaching a similar message, school authorities objected and said the red, white and blue buttons had to go. The other teachers relented, but Tankard resigned. ''This was a matter of conscience,'' Tankard, 63, told The Record of Bergen County for Wednesday's editions.