Are they mercenaries?

There seems to be general agreement on the site that the Blackwell soldiers were mercenaries, with disagreement focused on what one's attitutdes towards them and their death should be. But is it right to call them mercenaries? The dictionary definitions of mercenary stipulate not only serving for money, but a willingness to serve anyone, including the enemies of one's nation, for money.

Does the latter fit Blackwell? Their web site -blackwellusa.com - says they offer services to the US military, private corporations, and friendly foreign governments. Well, they presumably wouldn't advertise their willingness to serve American enemies, but I suspect this claim is in fact true. Blackwell appears to relate to the US military the same as Raytheon or McDonnell-Douglas do. They provide services that the US military needs, and make money providing further services to other countries as long as the US government or military does not object. It is difficult to believe they would risk their relationship to the US military - which is surely key to their effectiveness - by offering their services to hostile nations.

So is a soldier who joins Blackwell any different morally from a US army engineer who joins Raytheon. Are they not both simply transfering within the military-industrial-security complex? This is not to defend Blackwell - I view the privatization of war with great trepidation as I do the privatization of incarceration in the US, an analagous phenomenon - merely to suggest that mercenary is not the right word to describe them. They're privatized US soldiers.