Query: Why did propsals about making the European sovereign debt assets more like the US Treasury?
Context: The European Central Bank had stepped up the buying of member nations debt. In response to the crisis of 2010, some proposals have surfaced for a collective European bond issue that would allow the central bank to purchase a European version of US Treasury bills. To make European sovereign debt assets more similar to a US Treasury, a collective guarantee of the member states' solvency would be necessary.[b]