Do we really need Fifth Generation fighters?

As with everyone here, I am a devote aircraft enthusiast who loves nothing more than to talk about new and old weaponry in the skies.
One thing bothers me about todays political climate though! Do we really need Fifth Generation fighters?

Ever since the end of the Cold War and the collapse of the Soviet Union, there has been no REAL threat to N.A.T.O. or Europe/North America. Anyone who thinks a nation like Yugoslavia or Iraq posseses the ability to defeat the US or Britain in an all out war is living in a fantasy world – and as everyone keeps suggesting when the topic is brought up, China is not a nation to be concerned about either militarily or politically. So what the hell are we doing investing millions (if not billions)of pounds and dollars in cutting edge fighter design?

The present day designs such as the F-15, F-16, F/A-18, MiG-29, MiG-31 and Su-27 all seem to fill our needs well enough. These aircraft were designed due to the tense political climate between East and West following the Second World War. No such stand off exists today!
There is no “Evil” Empire (not that the Soviets were evil, they were just different)threating World domination. Yes, the threat of nuclear war still exists, but what impact will an F-22 for example have against an ICBM? NONE!!!

Can anyone explain why we cannot save money by continuing production of current types and spend the extra money for development of new projects on something more useful, like the U.K.s N.H.S. or Transport system for example?