The Israelis do NOT lie.
Because once you've caught them in ONE lie, you know they're liars.
And if the Israelis are liars and the Palestinians are liars then you won't know who you can't believe.
Which directly contradicts Marlowe's "truth".
-or-
Renders it useless as you will know you can't believe either.
-but-
If you can't believe them and they're telling the truth can you not believe the truth?