No new edition available, but he recently published The Rights of Refugees Under International Law
The definition of "refugee" embodied in the United Nations 1951 Refugee Convention and its 1967 Protocol has been subscribed to by over a hundred states. Many of them, including Canada, have chosen to incorporate the definition in their domestic legislation, where it has worked its influence on decisions covering the granting of asylum or other forms of protection.
James Hathaways book provides an account and analysis of the 1951 Convention. He distinguishes five key elements of the refugee definition - alienage, risk to life or freedom, the failure of the home state to protect basic human rights, vulnerability on grounds of race or social group, and recognized exceptions to the asylum states duty of protection - and examines it against the background of its drafting history and the decisions of determination authorities, appeals tribunals and the courts.
Although he uses Canadian case law as a means to this end, the legal dilemmas he confronts apply in all countries bound by the convention.