The requirement of congressional approval for the U.S. Treasury to raise the total amount the government is permitted to borrow has become the focus of a bitter political clash between the Obama administration and the GOP over spending priorities. The chart below demonstrates how a once-routine act of Congress has become a "political weapon," according to Louis Fisher, who focused on the separation of powers during his more than three decades at the Congressional Research Service.

Al Jazeera has charted Treasury data showing the rise in the debt ceiling since 2005, alongside the number of times the words “debt ceiling” have been spoken on the floor of Congress. What the chart shows is that the ceiling was raised numerous times without significant debate until 2011, the first year in which Republicans began demanding budget cuts as their price for raising it. The resulting standoff prompted the credit rating agency Standard & Poor's to downgrade U.S. credit from AAA to AA+, making it more expensive for the government to borrow money.

"Continued debate over whether to raise the debt ceiling is not only a political weapon, but it threatens the fiscal reputation of the United States around the world," Fisher said. "The likely result: hesitation by other nations to buy our bonds, and the need to raise the rates to attract borrowers. Of course, higher rates will increase the budget deficit and further undermine U.S. credibility."

This week, Fitch, another major credit rating agency, warned it was also considering a downgrade in the country's credit rating.