Today the PA is 'at war' with Hamas and Islamic Jihad. When it is in their interests, the 'Al Aksa Brigades' start again. When it is in their interest, they have 'national reconciliation' with Hamas. The mistake you're making is looking at a snapshot of the moment and confusing it for a long-term strategic reality. Did you forget that the Palestinian population voted for Hamas?
from the article: Netanyahu is fomenting revolution in the West Bank