The recently announced agreement of Turkey and Armenia to recognize each other is a big deal. In itself, it almost justifies Barack's Nobel peace prize. Since the forced relocation of Christian Armenians during WW 1 by the failing Muslim Ottoman Empire as a potential fifth column in which 1 million to 1.5 million Armenians died, both sides have been at odds. Armenians both in the US and Armenia have been demanding that Turkey acknowledge past misdeeds, which some have labeled genocide.
For its part, Turkey has always denied responsibility for the actions of the Ottoman Empire although Turkey occupies the heart of the former Ottoman Empire. When he established modern Turkey, Kemal Ataturk westernized the Turkish alphabet making it very hard for Turks to read the voluminous documents from the past.
Why is this first step to better relations between Armenia and Turkey so important? Turkey and Armenia at peace with each other will make it easier to route oil from farther east through the area. Turkey is a member of NATO and a US ally. Turkey wants to join the European Union and this brings them closer to membership.
I am not an expert on the events of WW 1 and the Ottoman Empire, but I am currently reading A Shameful Act by Turkish historian Taner Akcam which covers that period. This bodes well for the soon to happen Arab/Israeli talks.