What impact did Karl Barth have on Roman Catholic theology?

I ran across a book on Amazon called [*Karl Barth, Catholic Renewal and Vatican II*](http://www.amazon.com/Catholic-Renewal-Vatican-Systematic-Theology-ebook/dp/B007VN2ZYI) . It seems strange to me that [Karl Barth](https://en.wikipedia.org/wiki/Karl_Barth) , a neo-orthodox Protestant, would have an impact like what the book's blurb says: > From the 1920s on, Karl Barth’s thought was received with great interest not only by Protestants but also by Catholic theologians, who analyzed it in detail. [...] Dahlke shows how the preoccupation with Barth's 'Epistle to the Romans' and the ‘Church Dogmatics’ triggered a theological renewal among Catholic theologians. What is an overview of Barth's impact on Roman Catholic theology?