A way to think about the Walt-Mearsheimer book and related controversies:
- To the (large) extent that the Armenian-American lobby ginned up support for a pointless and destructive resolution condemning sins of the Ottoman Empire, it advanced its own causes at the expense of larger American interests. The people who did this are mainly from one ethnic group (Armenian-American) and of one religion (Christian, notably Armenian Apostolic or Armenian Orthodox).
- To the (huge and obvious) extent that the Cuban-American lobby has muscled the United States into its small-minded and punitive embargo of Castro's Cuba these last 45 years, it has advanced its own causes at the expense of larger American interests. The people who have done this are mainly from one ethnic group (Cuban-American) and of one religion (Christian, notably Roman Catholic).
- To the (ongoing) extent that AIPAC -- the American Israel Public Affairs Committee, which calls itself "America's Pro-Israel Lobby" -- is trying to legitimize a military showdown between the United States and Iran, it is advancing its own causes at the expense of larger American interests. The people who are doing this are not from one ethnic group in the conventional sense but are mainly of one religion (Jewish).
To observe these patterns, and warn against them (including the disastrous consequences of attacking Iran), is not to be anti-Armenian, anti-Orthodox, anti-Cuban, anti-Catholic, or anti-Semitic. Nor is it to deny that members of each lobby claim, and probably believe, that what they're recommending is best for America too. But in these cases they're wrong. And noting these groups' power and potential to distort policy mainly means recognizing that James Madison's warnings about the invidious effects of "faction"* apply beyond the 18th century in which he wrote.
* Federalist 10: "By a faction, I understand a number of citizens, whether amounting to a majority or a minority of the whole, who are united and actuated by some common impulse of passion, or of interest, adversed to the rights of other citizens, or to the permanent and aggregate interests of the community."