Who says there is no unity?
Mahmoud Abbas, faced with a decision to support or oppose Hamas terror, decided that terror is the way to go. He praised the Hamas "resistance" - which means he is praising rockets to Jerusalem and Tel Aviv.
Here is the official announcement from the PA leadership (translation by MEMRI):
The Palestinian leadership, headed by Mahmoud 'Abbas, held an emergency meeting tonight to study the recent developments in the national activity, as part of its confrontation with the criminal terrorist aggression being carried out by Israel against our steadfast people in the brave Gaza Strip.Abba Eban famously said that Arabs never miss an opportunity to miss an opportunity. In this case, though, a different rule is in effect:
The leadership heard the announcement by President Abu Mazen at the beginning of the meeting, and expressed its appreciation for the efforts that he has made on the international and regional level and for [his efforts] to connect with the leaderships of Hamas and Islamic Jihad. [The leadership] stressed the importance of continuing these efforts, and of continuing the coordination and the joint activity on all levels. This comes as part of strengthening the Palestinian national unity under the flag of the PLO, our only legitimate representative.
[The leadership] praises the steadfastness of our people in its courageous resistance against the occupation army that is carrying out ongoing massacres and crimes.
The leadership has stressed that our entire people, both in and outside the homeland, stands assertively alongside Gaza and alongside its bleeding people, at every hour, in defense of the Palestinian homeland, the rights of the people, and the national Palestinian enterprise.
The heroic Gaza is today [our] defensive shield, because it heads the ranks to protect our land, our rights, and our steadfast and sacred goals of liberation, return, and independence.
The Palestinian leadership has called on our people to take the most extensive and ongoing popular action in order to express steadfastness alongside the heroic Gaza and its courageous resistance and against the army of aggression and its ongoing crimes. We are certain that Gaza will not break as long as it [enjoys] the cohesion of our entire people...
Likewise, the Palestinian leadership has called for expanding the campaign of international solidarity with the brave and steadfast Gaza, for calling on all the international organizations and bodies, for condemning the crimes of the occupiers, and for acting intensively to prosecute its leaders and senior officials in international courts for these crimes. Also, it calls on the entire world to reject the misleading propaganda being spread by the government of the occupation and the aggression."
Gaza's demands for a halt to the aggression and the removal of the siege, in all its forms, are the demands of the entire Palestinian people, and it is to the implementation of this goal that the Palestinian leadership is devoting all its capabilities."
Arabs, no matter how much they hate each other, will always hate Israel more.
Nothing is going to change that.
Of course, Hamas has no love for Fatah and Abbas. Their idea of "unity" has always been imposing their own, Islamic supremacist worldview on the more "moderate" factions. Abbas happily goes along with this, because deep down there is no ideological difference between his party and Hamas, just he is more sensitive to Western pressure.