Francis Fukuyama notwithstanding, we have not reached the end of history.
JP II was certainly badly damaged physically by the assassination attempt but his greatest successes were later including the fall of the Iron Curtain. He declined thereafter but still contributed major doctrinal encyclicals and held the line against all comers on doctrine. In the last analysis, he is a human being subject to the frailties of age. He will be known as John Paul the Great, joining Leo the Great and Gregory the Great. We will recognize that greatness more and more after he has gone.
More to be feared than anything else is a prolonged period of coma or complete disability, essentially an interregnum, which would allow Modernist termites room to manipulate in his name.
Finally, JP II may be motivated by an apparently unwarranted optimism that the UN or some successor organization might someday become a vehicle for the restoration of Christendom. Short of direct, divine intervention, that seems quite unlikely, now or ever. Prudence dictates that we remain American nationalists and interventionists (as necessary) and keep our sovereignty strong and our powder dry.
You make a good point. So the American founders set up a better system than the Catholic founders. Hmmm...