Standard&Poor’s, one of the three major credit rating agencies downgraded on Friday the USA credit rating, previously noted AAA, the highest possible level. The new rating AA+ is translating the worry of experts about the sustainability of US public finances, in the context of ever increasing public spending and public debt above $14.3 trillion. The debt deal signed by the Congress is projecting savings of $1.2 trillion, which S&P estimates to be insufficient. The triple A has been assigned to the United States since 1941 and guaranteed to the country the best possible interest rates on its debt. The downgrade could add up to 0.7 of a percentage point to U.S. Treasuries’ yields, increasing funding costs for public debt by some $100 billion, according to SIFMA, a U.S. securities industry trade group.