Much recent attention has been devoted to the relationship between human rights law and what is variously called the law of war, the law of armed conflict and international humanitarian law. Traditionally, international humanitarian law declines taking a position on the lawfulness of any given war, so as to better address the behaviour of combatants on all sides. Many now suggest that human rights law adopt the same approach. Some recent examples are the refusal of the big human rights NGOs, Human Rights Watch and Amnesty International, to take a position on the definition of the crime of aggression in the Statute of the International Criminal Court (see, e.g., http://www.hrw.org/backgrounder/ij/asp1107/).
My opinion is that this is all wrong, because it entirely overlooks the right to peace. One of the four freedoms first proclaimed by President Roosevelt and affirmed in the preamble of the Universal Declaration of Human Rights is 'freedom from fear'. Admittedly, the right to peace has been much neglected. But we can see manifestations of it in, for example, the obligation to prohibit propaganda for war set out in article 20 of the International Covenant on Civil and Political Rights. Aggressive war is a human rights issue.
My views on this are developed in a recent article, ‘Lex specialis? Belt and Suspenders? The Parallel Operation of Human Rights Law and the Law of Armed Conflict, and the Conundrum of jus ad bellum’, (2007) 40 Israel Law Review 592-613: http://www.mediafire.com/?fypn5om43vo