Long seen as a potential Achilles heel, satellite navigation and positioning systems are increasingly important pieces in the geostrategic stakes with Russia, and even more so with China.  On June 23, the final satellite of China's BeiDou System slotted into orbit.  The European Union is also scheduled to complete its own rival Galileo System this year.  In adition to building BeiDou, the Peoples Liberation Army has been developing the power to blind, disorient, and even destroy the United States' GPS System.  GPS is not a navigation system but a timing system.   Even automated share trading takes timing cues from GPS.  PLA military doctrine includes degrading and attacking the U.S. GPS System during both peacetime and wartime situations.  This includes substituting the BeiDou System fpr GPS smong present user states for economic and political advantage, developing capabilities for wartime targeting and deegradation of the system, and scenario development concerning potential first-strike capabilities against all U.S. C4ISR space-based assets, which include GPS.           C4ISR refers to command, control, communications, computers, intelligence, surveilance, and reconnaissance: everything from from spy satellites to military command satellites.  In other words, the PLA is wargaming scenarios that involve taking out satellite infrastructure.  In addition to explosives, satellites can be physically targeted by energy beams such as a high powered laser.  They can also have their electronic circuits fried by an eletromagnetic pulse from a nuclear device, or more likely from a precise microwave-emitting device or a limpet-like mine.  Attacks may also come from mobile 'on orbit' inspection satellites with robotic arms and other weaponized elements.  China is reported to have tested its DN-2 ground-based medium Earth orbit-capable anti-satellite interceptor in 2012, so it has likely had the ability to attack GPS satellites kinetically since the middle of the last decade.  When China starts to construct its first Space Station in 2021, it will use a module-based structure similar to the old Soviet MIR Space Station.  This means China can loft armed 'combat modules' when desired, which most likely will be able to attack GPS and most other satellites.  Another option is to physically target the ground-based systems that provide updates and support, which would lead to gradual degrading of the system.  Cyberattacks are a key possibility. Or they could try to infect the satellites with something that would screw up the timing signals.  Another form of e;ectronic attack is jamming.  They could jam terrestrially where the signall is received, or put something into orbit and try and jam the signal from space.  Jamming however can be detected and tracted through its tell-tale electromagnetic signal.  Methods such as jamming and cyberattacks on GPS also suit the PLA's preferred modus operandi of wrestling in the geopolitical shadows rather than employing open warfare.  Greg Autry, a space expert and co-author of "Death by China", has been warning about the threat from China's space programs for two decades.  He says that in the past two to three years, the defense community has become clear about the threat.  Also that the GPS threat can't be looked at in isolation.  He warns against assuming the CCP is a rational actor like democtatic nations. He says "The fact that the Chinese are obviously targeting the global positioning system should give the entire world pause.  They are preparing to take that out", he said. "The role of the Chinese government is not to ensure the prosperity and happiness of its population, as is the role of the U.S. government.  "The role of the Chinese government is to ensure the continuation of the Communist Party at all costs and the people and the economy are a tool to achieve that goal".  --This is from an article in THE EPOCH TIMES---