DLA Piper announced Monday that its ex-chairman, former Senate majority leader George Mitchell, Jr., is returning to the firm after a two-year absence.

Mitchell was serving chairman emeritus of DLA when he resigned from the firm in February 2009 to serve as the Obama administration’s special envoy for the Middle East. But peace in that troubled region has been elusive, and Mitchell, who helped broker a historic agreement in Northern Ireland during the Clinton administration, stepped down last month amid an impasse in negotiations. (Mitchell spoke with Reuters on Monday about the stalled peace process and returning to DLA.)