Are Unions today driving society to the brink of Insolvency in America?

Unions are much weaker today have a much smaller fraction of the work force than they did 50 years ago. when our economy performed much better. Also there are counties that are much more unionized now than the US, like Germany, that are performing better. It would be nice to think all we had to do to fix our problems is to get rid of unions, but unfortunately things are not that simple.