Air carrier Captain reported GPS jamming and spoofing during cruise in a known area or reported GPS interference. The GPS signal was restored after transitioning the area and the flight continued to destination.

Narrative

A couple of hours prior to departure; I asked Dispatch to change our routing near Rafah and Gaza and the Israel FIR to a more Western route closer to Cairo and a more southern route for the big turn to head out over Saudi Arabia bound for Kuwait. We didn't have military ordinance or explosives on board. Dispatch granted my request. Approaching the North shore of Egypt; I noticed our GPS positions starting to become erratic. So we were at FL390 On the L560 airway 60 miles north of VUTAR intersection. The GPS on board; and our iPads showed our position directly over Beirut; which was incorrect. Then as we passed over VUTAR on the same airway; our GPS was spoofed again; and showed our position directly over Cairo; which was also incorrect. GPS left and right continually showed position on international airport. We had EICAS messages… UNABLE RNP; TRANSPONDER L AND TRANSPONDER R; TERR POS. All other systems were normal. The GPS was then restored between WEJ and NADIK on the L604 airway.ATC is aware of GPS jamming in the area. Many other planes were asking for position verification from ATC. I was cross checking VOR radial and DME the whole way through there and everything checked OK. I'm glad Dispatch gave us a more Westerly route and a Southerly route to make the corner to head over Saudi Arabia.The cause of this is the war on Gaza and Israel and terrorism in the region and GPS spoofing. I'm not sure how the GPS is signals are able to send out the erroneous info or be hacked into or whatever it is the bad guys do.I suggest dispatch route us farther to the West of Gaza and Israel airspace. Why take the risk of taking on missile fire and position errors? It is a good idea to verify position with ATC and also take additional measures to verify your position with VOR radials and DME.