Why does the author use the phrase “without clearly realizing what international justice is“ (lines 27 - 28) in the context of German people?

Answer this question based on the following passage.

            The Germans were formerly the best fighting
            men and the most warlike nation of Europe.
            Germans have bled and conquered on
            countless battlefields in every part of the
(5)        world. In striking contrast to this military
            attitude they have today become a peace
            loving nation. The change springs first from
            the reverses the Germans suffered in the
            two world wars, but also in part from the
(10)      good-natured character of the German
            people, which finds intense satisfaction in
            doctrinaire disputations and partisanship,
            but dislikes pushing things to an extreme.
            It is connected with another characteristic of
(15)      the German nature. Our aim is to be just,
            and we strangely imagine that all other
            nations with whom we exchange relations
            share this aim. We are always ready to
            consider the peaceful assurances of foreign
(20)      diplomacy. We obstinately resist the view
            that the political world is only ruled by
            interests and never from ideal aims of
            philanthropy. "Justice," Goethe says aptly,
            "is a quality and a phantom of the Germans."
(25)      We are always inclined to assume that
            disputes between States can find a peaceful
            solution on the basis of justice without clearly
            realizing what international justice is.
            An additional cause of the love of peace,
(30)      besides those which are rooted in the very
            soul of the German people, is the wish not
            to be disturbed in commercial life. The
            Germans are born businessmen, more than
            any others in the world. Notwithstanding the
(35)      reverses in the none-too-distant past, we
            have made marvelous progress, and our
            young industries challenge competition with
            all the great industrial states. German
            merchants traverse every quarter of the
(40)      globe. Under these conditions our national
            wealth has increased with rapid strides. Our
            trade and our industries -- owners no less
            than employees -- do not want this
            development to be interrupted. They believe
(45)      that peace is the essential condition of
            commerce.