The real questions to be asked here isn't do we think Lance doped or not, but why is this a focus of a Justice investigation? What greater good can this use of tax dollars and stretched resources possibly serve? Ah, but I have an answer......
The Eurozone debt crisis is the fundamental reason. With the Syriza party poised to gain greater power in Greek elections this weekend and potentially unravel their buyout deal, this puts greater stress on the French and German relations who orchestrated it in the first place. With Sarkozy now out and new French Prime Minister Ayrault now in power, there is a very fragile support in France to continue salvage not only the Greek deal but also the looming issues in Spain and Italy. If France backs off from their efforts with Germany to address the problems, leaving Germany as the only Eurozone country with the economic resources to save Europe, there will be insufficient support and the entire European economic region will suffer severe collapse, hammering the rest of the global economies at the same time.
The French have long hated Armstrong, and his winning of "their" race 7 times has been a symbol of national disgrace as he destroyed the record of their great cycling champion Bernard Hinault. This has been a long standing issue in French pride, and they harbor deep and ill feelings to this day. For the US, this issue is a leverage point that can be used to help address the Euro debt crisis.
It would be very difficult for the US to step in directly and help support any European bailout efforts. Besides being economically limited ourselves, the political ramifications of the US riding into Europe to force a direction would be untenable to the Eurozone member nations. But if we can use leverage to help hold France together with Germany, then the two strongest nations in the region still have a chance of dealing with Greece, Spain, Italy, and the other fragile nations. By agreeing to take down Armstrong through doping charges, the US can restore French pride once again and help provide greater power to Ayrault in his efforts to placate the French citizens who are anathema to a Greek bailout. With the great legacy of Hinault restored, the French can once again feel superior in the region and will be again willing to help dictate to their neighbor nations how to run their finances. The French-German alliance will be restored, and they will be able to use their joint influence in the Eurozone to force the changes required to restore economic stability.
So, for a few million dollars of Justice department resources, the US can orchestrate the actions needed to rescue the teetering Eurozone economies and keep stability in the world investment markets - a brilliant and amazing bargain!!!
(Ok, of course I don't really believe this. But it makes as much sense as some of the other conspiracy theories surrounding Lance!)