As Direland points out, Marcuse's thought unfortunately has diminished since his death in 1979, in no small part because of the powerful intellectual trend of the 1980s and 1990s of post-modernism (while the intellectual reputations of his peers, especially Theodor Adorno and Walter Benjamin, have remained steady or risen), but many of this works, especially Eros and Civilization, One Dimensional Man, An Essay on Liberation, and the Aesthetic Dimension (which I'd hoped to use in my aesthetics course but didn't have space for), are directly applicable to the society we find ourselves in today. There's a lot more on the Direland site, including a brief remembrance by critic Jeff Weinstein, who was at UCSD during Marcuse's late career sojourn there; a stub (there's no better term for it) by Ariel Dorfman; and links to a site set up by Marcuse's grandson Harold, who teaches at UC Santa Cruz, and a film on Marcuse, which explores not only his philosophy but his personal courage (he came under attack by none other than Ronald Raygun); and more!
For those interested in even more intellectual heavy lifting, Perry Anderson presents an excellent reading, entitled "Arms and Rights," in New Left Review of the views of three major contemporary liberal philosophers--late Harvard philosopher John Rawls, second-generation Frankfurt School theorist Jürgen Habermas (whom I saw speak this past year on this exact topic and on the W administration's actions in Iraq and various European governments' and societies' responses), and late Italian scholar Norberto Bobbio, on the concept of serial war and global peace, and in particular, of Immanuel Kant's idea of "perpetual peace."
I won't even attempt to describe or summarize it, but it's worth looking at, especially if you have any familiarity with Kantian political thought. Here's one quote:
Of the three, it was Rawls who offered the most systematic outline of a desirable international order. The Law of Peoples extends the modelling devices of A Theory of Justice from a national to a global plane. How is international justice to be realized? Rawls argues that we should imagine an ‘original position’ for the various peoples of the earth parallel to that for individuals within a nation-state. In it, these collective actors choose the ideal conditions of justice from behind a veil of ignorance concealing their own size, resources or strength within the society of nations. The result, he argues, would be a ‘law of peoples’ comparable to the contract between citizens in a modern constitutional state. But whereas the latter is specifically a design for liberal democracies, the scope of the former extends beyond them to societies that cannot be called liberal, yet are orderly and decent, if more hierarchical. The principles of global justice that should govern democratic and decent peoples alike correspond by and large to existing rules of international law, and the Charter of the United Nations, but with two critical corollaries.
This is only the beginning, though; he examines their uses of Hegel, America as a superpower, "Nato's moral order," and so much more.