An air carrier captain reported GPS jamming and its continuation during the remainder of the flight.

Narrative

Flight was routed near White Sands to avoid hazardous weather en route. The flight got a GPS invalid FMC message. Many aircraft queried ATC about the GPS jamming and ARTCC confirmed that jamming was being conducted. I reviewed training concerning GPS Signal interference and ran the QRH GPS Data Unreliable procedure. Seeing that neither GPS units indicated a position; I selected GPS updating off per the QRH. I also ensured that all conventional navigation sensor updating was enabled. Shortly thereafter; the GPS Light illuminated. That seemed to be the consequence of selecting GPS Updating OFF; but that behavior is not expected and seemed contrary to training. I ran the GPS Light QRH procedure. I told the FO/PF to review the manuals and QRH for himself to ensure we had a common understanding of the situation.The GPS units never recovered. Hundreds of miles beyond the interference area; we still had no GPS positions. As we approached top of descent; we formulated a plan for the approach. The active runway had GPS; RNP & VOR approaches. (Winds were out of limits for the ILS to the reciprocal runway. The parallel runway was closed which made its ILS unavailable.) Clearly we could not do the GPS or RNP approaches with two failed GPS units and the GPS light illuminated. That left the VOR approach. The QRH GPS Light procedure says; Continue normal operation if ANP meets the requirements for the phase of flight;" so that would allow the VOR overlay; provided that actual navigation performance (ANP) meets the 1 nm terminal standard. But what if it doesn't? The QRH offers no guidance. Common sense would indicate that one cannot continue to use an approach procedure if the system falls below the required navigational performance; but the QRH only says things like "verify position" but not to abandon a non-RNP approach. How can the pilot "verify position" to a tighter standard than the INS (Inertial Navigation System) which is integrating multiple sensors with 0.1 nm resolution?Also; our procedures for non-ILS approaches direct selecting VOR Updating OFF to prevent a map shift. That seemed inadvisable in this case; because; with no GPS positioning; we were relying on VOR & DME updating to prevent dead reckoning drift of the IRS units. I made the decision to leave VOR Updating ON; which I believe is consistent with QRH procedures.We also got a light on the transponder control panel due loss of ADS-B in conjunction with the GPS failure; but ATC continued to receive our IFF Modes A&C.We discussed the possibility of the need to fly the VOR approach using only conventional navigation if the ANP was insufficient to perform an overlay using LNAV & VNAV. Here is one of the main safety issues I want to highlight: Our non-ILS procedures ONLY contemplate using a GPS overlay to fly VOR/LOC approaches using LNAV/VNAV. ***We have no procedure for or TRAINING in flying a VOR approach using only VOR data.*** In fact; our training department goes out of its way to discourage non-VNAV vertical modes (VS or LVL CHG); and it pretends that the ability to couple the autopilot/flight director (AP/FD) to a VOR source does not exist. For example; to track a radial outbound; we are taught to create a fix some distance out on that radial and track inbound to it using LNAV rather than the much more straightforward technique of tuning the navigation radio to the VOR frequency; setting the outbound course on the mode control panel (MCP); and selecting the VOR/LOC lateral mode. (I.e.; using Cat I navigation the way that the aircraft was designed to.)I pressed the PF to think through the specific actions he would perform on the MCP to conduct a conventional VOR approach without the use of LNAV/VNAV should the reliability of our position degrade to the point that LNAV/VNAV was not available. I had to instruct him on setting the navigational display to VOR; selecting VOR/LOC for lateral guidance; and using non-VNAV modes to descend; because*our company training is totally silent on this topic.*Let's pause for a moment to review the cards stacked against us: Night. Mountainous terrain. Unreliable position. Degraded EGPWS. The captain (PM) has never landed at this airfield. The first officer (PF) has been there once. The PF has approximately one year on the aircraft so he has not yet fully internalized the use of non-VNAV vertical modes. He is being introduced to the required lateral mode for the first time. Neither pilot has flown this type of approach using the techniques that will be required on this type aircraft; in real life or in the simulator; because it is completely absent from Company training and even Company operating manuals. And; oh; by-the-way; the charted glideslope is steeper than normal (with only a VASI rather than PAPI for guidance).All of this because the Air Force wants to play games with the Global Positioning System.The only things we had going for us were CAVU meteorological conditions and the experience that each pilot accumulated prior to coming to this airline. On initial contact with TRACON; we stated we were non-GPS and requested vectors to the VOR approach. We initially got behind the descent and Approach Control had to vector us around for another try. On a vector to intercept the final approach course; we received an UNABLE REQD NAV PERF-RNP message which meant we could no longer fly the VOR as an overlay. I was not aware there was a QRH procedure for this at the time; but its steps had already been accomplished. We flexed to VOR navigation only without using LNAV/VNAV as we had briefed; setting each intermediate step-down altitude in turn and capturing the final approach course with VOR/LOC. The PF chose to use LVL CHG which added new meaning to the term "dive & drive." With a couple sink rate calls from the PM (with prompt PF corrections) between 1000' and 500' (in VMC); we were safely on deck.The GPS Light was still on at the gate so we wrote it up in the eAML.Cause: USAF disruption of GPS signalsInadequacy of trainingSuggestions: For USAF; stop degrading navigation within our national airspace.For USAF; issue NOTAMs describing time & location of GPS signal jamming & spoofing.For Dispatch; route aircraft around areas of known/reported/suspected GPS signal jamming/spoofing.For Fleet Managers; develop flight procedures to be used when LNAV/VNAV (and analogous Airbus modes) are not available due to loss of required navigational performance.For Training; conduct training on conventional navigation modes and techniques with emphasis on techniques to be used for non-ILS approaches when LNAV/VNAV modes are not available."