LONDON  The bond vigilantes are back.

But this time they are roaming mostly through Europe rather than the United States  at least for now. Their mission: to force governments to cut budget deficits that have ballooned in the wake of the financial crisis.

As big investors in the credit markets, activist bond traders developed a fearsome reputation in the early 1990s by pushing up yields on Treasuries in order to force the government to tame large deficits. Their most famous target was a newly elected president, Bill Clinton, whom they pressured to abandon campaign promises of tax cuts.

Today, the bond market posse has set its sights on Europe  particularly Britain and Greece  where stagnant economies and high levels of government spending have led to the highest budget deficits in the region.

Although the left-leaning governments in both countries are struggling to show investors that they have a workable plan to reduce deficits  which now average around 13 percent of gross domestic product  bond traders are increasingly demanding higher interest rates to reflect the rising risks.