The perpetrators of the Armenian Genocide were the menebers of the nationlistic political movement Committee of Union and Progress (ealier Young Turks). The Armenians and other Christian minorities became the scapegoats of a failed nationalistic agenda. The Ottoman Empire lost a series of wars against the Balkan states and Russia, and in nationalistic circles especially Armenians were pointed out for being in aid of advancing Russian armies in eastern Anatolia and Caucasus. The Armenian minority had already been rebellious against the Ottomans in the late 19th century, and these developments were used by Ottoman officials (like Talat Pasha) to justify the forced deportation of the from areas they meant to be risky to have Armenians living. The deportations were carried out by the regular Ottoman army and irregular kurdish tribal forces. Under the large scale deportations acts of genocide were committed by some of these forces. The regular and irregular forces carried out sacking of villages and mass killings, and in some cases civilians participated in the atrocities. Turkish sources point out that the armed forces and the civilian population were fueled by revenge for act carried out by the earlier invading Russian army andcm irregular Armenians aiding the Russians. The Armenians were much needed local supporters to the advancing Russians, and they were optimal allies because of their religious and cultural similarities. This were one of the main factors behind Armenians being singled out in the eastern provinces as traitors and rebels against the Empire. I would conclude that the main to factors were, firstly the nationlistic policies carried out by the CUP and their demonizing of the Armenian population as scapegoats for their own failing expansionist policies. Furthermore secondly the rebellious state if the Armenians, and their support of the invading Russian amry increased support of the CUPs claims throughout the Otto.man Muslim population.

The invading Russian army had themselves committed acts of genocide against the Muslims in the Caucasus and Eastern Anatolia. Some Turkish historians and critics of the Armenian Genocide use these acts for justifying the Ottoman atrocities, but this a very discredited way of thinking. The reality is that both the invading Russians and Ottomans commited Genocide and millions of people were brutally murdered or deported.

This is just brief introduction to this big topic, if there anything you want an in depth analysis of or explained further feel free to ask.

Sourced.

Akçam, Taner. A shameful act: The Armenian genocide and the question of Turkish responsibility. Macmillan, 2006.

Akçam, Taner. The Young Turks' crime against humanity: The Armenian genocide and ethnic cleansing in the Ottoman Empire. Princeton University Press, 2012.

Dadrian, Vahakn N. The history of the Armenian genocide: ethnic conflict from the Balkans to Anatolia to the Caucasus. Berghahn Books, 2003.

McCarthy, Justin. Death and exile: the ethnic cleansing of Ottoman Muslims, 1821-1922. Princeton, NJ: Darwin Press, 1995.

McCarthy, Justin. The Ottoman peoples and the end of empire. Oxford University Press, 2001.

What armenian crusades are you referring to? The atrocities in question is 1915 Genocide, right? Just wanted to be sure before writing a long comment.

The Crusades and the Armenian Genocide were hundreds of years apart and unrelated.

The Ottoman empire was falling apart and a sense of Turkish national identity was forming among Ottoman Muslims. They had committed massacres against Balkan Christians, but the western great powers stopped this and Russia achieved independence for the Balkan states. However, it became clear throughout the late 19th century after the Hamadian massacres and Adana massacres that the great powers did not care what happens east of Constantinople. The Young Turks came to power and wanted to create an ethnically and religiously homogeneous nation of Islamic Turks. The Armenians were ethnically cleansed from their homeland and their lands were taken as living space to create a "Turkey".

German vice consul Max Erwin von Scheubner-Richter who was in the Ottoman empire described how small acts of Armenian self-defense were portrayed as large rebellions and for what purpose:

I have conducted a series of conversations with competent and influential Turkish personages, and these are my impressions: A large segment of the Ittihadist [Young Turk] party maintains the viewpoint that the Turkish empire should be based only on the principle of Islam and Pan-Turkism. Its non-Muslim and non-Turkish inhabitants should either be forcibly islamized, or otherwise they ought to be destroyed. These gentlemen believe that the time is propitious for the realization of this plan. The first item on this agenda concerns the liquidation of the Armenians. Ittihad will dangle before the Allies a specter of an alleged revolution prepared by the Armenian Dashnak party. Moreover, local incidents of social unrest and acts of Armenian self defense will deliberately be provoked and inflated and will be used as pretexts to effect the deportations. Once en route, however, the convoys will be attacked and exterminated by Kurdish and Turkish brigands, and in part by gendarmes, who will be instigated for that purpose by Ittihad.