Reducing the exposure of the U.S. government to future Social Security and Medicare liabilities will take great political leadership.

David Walker, comptroller general of the United States, makes that prediction in a letter summarizing an analysis of efforts in European countries and other developed countries to reduce government exposure to pension programs, retiree health programs and other social welfare programs.

Walker’s agency, the U.S. Government Accountability Office, prepared the analysis for the Democratic and Republican leaders of the Senate Budget Committee.

GAO analysts look specifically at reform efforts in countries such as Germany and the Netherlands.

One implication is that “for reform to be enacted and sustained, it needs broad-based support that reaches across parties and groups,” Walker says.

Moreover, trying to achieve broad reform by making a series of limited changes may be a bad idea.

“In some cases where several rounds of reforms occurred, frequent changes to pension systems created public mistrust,” Walker writes in his letter.

A copy of Walker’s letter is available