What I'm reading:

Just James: The Brother of Jesus in History and Tradition

We cannot know if Paul journeyed to Rome with no regrets or whether James experienced forebodings not only concerning his own future and the future of his nation but also (and especially) concerning the future of Christian Judaism. James struggled to maintain the messianic faith in Jesus as a viable faith for Jews. The weight of history crushed him and his tradition so that scarcely an adequate memory remains of his heroic struggle.