Turkey doesn't want it called a "genocide", and so Obama reneged on a campaign promise. From Yahoo news,
Yerevan says that the Armenian massacres are today recognised as genocide by 22 countries, including France and Russia, as well as the European Parliament and the Council of Europe.
US President Barack Obama had pledged in his campaign that he "will recognise the Armenian genocide" if elected, but has thus far avoided using the politically charged term, stressing however that his "view of that history has not changed".
His "view of that history has not changed" and yet he now will not refer to it as a genocide despite saying he would. It sounds to me as if he is trying to appease the Armenians while not crossing the Turks.