The need of an independent GPS system is emphasised in the 2008 South Ossetia war where the GLONASS was not yet ready and Russia was still using GPS in most of their weapons.
Instead of a swift victory for the Russians, the war has been 'barbaric' as they can't use their precision guided weapons against the Georgians as the US blacked out the Georgian map during the war. GLONASS wasn't ready yet so they fought the war with brute force and the war did not end the Georgian government. Military analysts criticised how the war was fought and the Russians were very inefficient and did not use their smart artillery and precision strikes and commited troops without these GPS guided technology. Although it was a victory for the Russians, it also shows that their military force is weak due to their inefficient use of weaponry, inability to take advantage of their own GLONASS, and the Georgian army was able to inflict heavy casualties against them.
I'm pretty much afraid of what China will do with their own GPS. Practically, they are claiming that they own the whole south China sea and beyond, they are claiming territories that extend beyond their internationally mandated borders and are willing to harass anyone who gets in their way. Their logic is also getting childish and they are willing to shoot anyone who goes into these disputed waters and yet, they think that they are the only one who has the right to sail there because they are large and powerful.