It appears that in the case of Libya, the answer is yes.
After more than twenty years, the US is restoring normal diplomatic relations with the regime of Muammar Khaddafi. Well before the Iraq War, the US government had opened a diplomatic dialogue with Tripoli to work toward dismantling its WMD programs. The two reached an agreement, and have now normalized relations. This notwithstanding the fact that Mr. Khaddafi’s government remains rather ugly and reprehensible in ways too numerous to count.
It’s a lesson we should keep in mind, particularly with respect to certain other US relationships in the news today. We can negotiate with odious regimes.
And sometimes, good can come of it.