The U.S., nearly everyone presumes, is a long way from the fates of Greece, Portugal and Ireland. Even so, with both Moody’s and S&P threatening credit downgrades this week, it would be logical for some investors to feel a bit unnerved about Treasury bonds and demand higher interest rates.

Yet so far, that isn’t happening. The yield on two-year Treasury notes ended Friday at a mere 0.36%, down from 0.39% a week ago and near the 2011 low of 0.33% reached June 24. The 10-year T-note yield ended the week at 2.91%, down from 3.03% a week ago…

Wall Street, usually prone to overreaction, remains underwhelmed by the ratings-cut threats. Why? There is disbelief that the cuts really will happen. Congress must raise the $14.3-trillion federal debt ceiling by Aug. 2 or risk the Treasury running out of money, but by Thursday there was talk in Washington of a compromise between President Obama and Republican leaders that would avert that potential debacle.

What’s more, investors rightly are suspicious of the ratings firms. There is the sense that Moody’s and S&P are playing hardball with Uncle Sam because their reputations are so tarnished by the many AAA ratings they handed out to mortgage bonds that crumbled with the housing bust.