It's a well-worn path.
USA/Russia - War (Good vs Cheap), Detente (Nuclear brinkmanship, Cold war), Disrupt (new economies), Decline (high cost of supporting existing infrastructure/policies)
RIM/Nokia - War (Good vs Cheap), Detente (stuck to their product lines), Disrupt (Touch replaced T9 / Qwerty), Decline (high cost of losing customers & late entry to new markets)
Apple/Google - War (Good vs Cheap), now settling into a comfortable Detente. They're not stupid. They both know there will be a Disruption. It won't come from Microsoft and Blackberry making "me too" phones.
Apple will try and do it themselves, with loads of secret R&D. Google are trying to do it with loads of public R&D (driverless cars, Glass, Nexus Q, Ingress).
But it's inevitable. One day, some other company will blindside them and Disrupt them utterly.