Meanwhile, members of the House Projection Forces Subcommittee had been pressing the Navy to use nuclear power for major combatants, partly as a response to concerns about the price and availability of oil. They prompted studies in 2005 and 2006, the second of which stated that nuclear power broke even at an oil price of $70–$225 per barrel for escort ships of 21–26,000 tonnes with heavy radar use. This led to a requirement in the FY2008 Defense Authorization Act that all major combatant vessels be nuclear powered unless it was not in the national interest.