But check for yourself. You can read the CBO (Congressional Budget Office) document Long Term Budget Outlook for yourself. The problem in the US is the out-of-control health care system. Not Social Security. Here's the relevant graph from the appendix:
But you won't get the truth from the right wing nuts in the US. Their agenda is to destroy government (remember mantra "government is not the solution to our problem; government is the problem" by Reagan in his first inaugural address?). They have had a very successful agenda for the last 30 years of diverting government monies from the bottom 98% of the population into the hands of those of the top 2%. Destroying all the social entitlement programs is part of this agenda. This effort has been wildly successful. The rich are far richer today than 30 years ago. This is a new "Gilded Era" where the rich dominate everything and income inequality has grown beyond the wildest dreams of the avaricious rich of the 1950s and 1960s where they still felt a social obligation to contribute as part of society. Now they view society as a buffet laid out for them to feast on, take but never give.