The old world nobility that he celebrates also couldn't find outlets for its desire to serve outside of war.
When the war finally came, it swept that class away.
I would say it is not "commercial world" but what he calls Americanism, acerbically adding "without the national qualities of Americans". Do you really think that interest in national and religious identity is nothing more than "trouble with the commercial world"? Do you think France or Germany prior to 1914 did not live in the "commercial world"?