Air carrier pilot reported GPS jamming on approach to AMM. The reporter was unsure of the procedure to follow if they had been forced to divert.

Narrative

Starting at 6;000 ft. during descent into AMM we started getting all of the warning the most current pilot bulletin and supplemental procedures said we could get. Everything from unable RNP; too low; to terrain terrain pull up. These warnings persisted all the way down to 300 ft. We were following procedures by having the GPS off and no HUDs. We were day VFR so we were able to continue the arrival and approach without having to perform an escape maneuver. What would have happened if we were night or IMC ? Would we try the approach again assuming we would get the same warnings or do we divert ? When the war started in Israel; dispatch was using ZZZZ1 and ZZZZ2 as alternates. These airports are outside of the known spoofing areas. Dispatch is now using a local airport (ZZZZ3) as an alternate. This airport is only 30 minutes away and well within the known spoofing area. Should we be using an alternate in an area of GPS anomalies ? What if we have an engine failure on takeoff ? Do we dare come back to an airport in an area of know GPS spoofing? Do we divert to an airport that's within this same area? Or do we leave the region ?