"Palestinians are occupying Jewish land..." Which UNSC resolution? " Is that an act of war?" No. Occupation is the result of war. The UN doesn't care with Contracting Power occupies a non-state entity as long as they uphold the Geneva Conventions. Israel has not. Never the less, as the Palestinians are not a state, they cannot be a Contracting Power. (the Arab states were in the wars) The Palestinian attempt to sign to the GC's was rejected because they were occupied & therefore could not declare themselves a Sovereign State.
One student killed, three wounded at Arizona campus during fight (a)
from the article: Palestinians under world pressure not to declare state unilaterally