In short, because Turkey denies that Armenians were the victims of a state-planned, deliberate policy of genocide, and some are reluctant to offend a supposed ally.
On October 11, 2007, Turkish Prime Minister Erdogan’s government released a statement that declared, “It is not possible to accept such an accusation of a crime which was never committed by the Turkish nation.”
And writing in the Wall Street Journal on October 19, 2007, Mr. Erdogan asserted, “The truth is that the Armenian allegations of genocide pertaining to the events of 1915 have not been historically or legally substantiated.”
The Turkish government funds a multi-million dollar genocide denial campaign which includes public relations firms, high-priced lobbyists, and even a handful of academics. Turkey has disrupted foreign academic conferences on the Armenian genocide, has threatened to limit ties with governments that recognize it, and has stifled domestic discussion of it by prosecuting dissenters under a law that prohibits "insulting Turkishness."
Whatever the stated motivation, the Anti-Defamation League’s failure to acknowledge unambiguously the Armenian genocide and its opposition to U.S. recognition of the genocide, makes it complicit in this international genocide denial campaign.