The question HOW GERMAN IS IT underlies the conduct and actions of the characters in Walter Abish's new novel, an icy panorama of contemporary Germany, in which the tradition of order and obedience, the patrimony of the saber and the castle on the Rhine, give way to the present, indiscriminate fascination with all things American. On his return from Paris to his home city of Wurtenburg, Ulrich Hargenau, whose father was executed for his involvement in the 1944 plot against Hitler, is compelled to ask himself, "How German am I?"--as he compares his own recent attempt to save his life, and his wife Paula's, by testifying against fellow members of a terrorist group, with his father's selfless heroism.