Well their rise came with Berlusconi and their decline came with the decline of Berlusconi, they have no money anymore to spend like in the 90's till 2004/2005 when Berlusconi was in his prime time as politician, and they wont rise again untill a investor comes to spend some money for new players or they start to establish a good new generation of young players and play attractive football, lets say like dortmund with a brilliant coach.
edit: here the years they won the CL : 1962/63, 1968/69 <gap> Berlusconi era 1988/89, 1989/90, 1993/94, 2002/03, 2006/07