Here, if Palestine should declare itself vulnerable to unforeseen dangers, perhaps even from the interventionary or prospectively occupying forces of other Arab armies, it could lawfully end its previously codified commitment to remain demilitarized.
Another factor explains why Netanyahu’s hope for Palestinian demilitarization was, and still is, ill-founded. After declaring independence, a new Palestinian national government could point to certain pre-independence errors of fact or to duress as fully appropriate grounds for agreement termination. The usual grounds that may be invoked under domestic law to invalidate contracts can also apply under international law, both to actual treaties and to treaty-like agreements.
Any treaty or similar agreement is void if, at the time of entry, it is in conflict with a “peremptory” rule of international law, a rule accepted by the community of states as one from which “no derogation is permitted.” Because the right of sovereign states to maintain military forces for self-defense is always such a rule, “Palestine” could be within its lawful right to abrogate any compact that had previously, before independence, compelled its demilitarization.
Netanyahu should take no comfort from any legal promises of Palestinian demilitarization. Should the government of any future Palestinian state choose to invite foreign armies or terrorists on to its territory, possibly after the original government had been overthrown by even more militantly jihadist/Islamic forces, it could do so not only without practical difficulties but also without violating international law.
The core danger to Israel of any presumed Palestinian demilitarization is more practical than legal. The U.S.-driven Road Map stems from a very basic misunderstanding of Palestinian history and goals. At a minimum, President Obama should recall that the Palestine Liberation Organization was formed in 1964 – three years before there were any “occupied territories.”
Inevitably, any Palestinian state would be ridden by inequality, violence, and strife. To get an idea of what this boiling cauldron would actually look like, one need only look today at Syria.
If you like Syria, you’ll love Palestine.