In Thomson-CSF v. Evans & Sutherland Computer Corp., 64 F.3d 773, 776 (2d Cir. 1995), the Court focused on the distinction:
"the circuits have been willing to estop a signatory from avoiding arbitration with a nonsignatory when the issues the nonsignatory is seeking to resolve in arbitration are intertwined with the agreement that the estopped party has signed. . . . The nature of arbitration makes the distinction important. Arbitration is strictly a matter of contract; if the parties have not agreed to arbitrate, the courts have no authority to mandate that they do so. Thomson . . . cannot be estopped from denying the existence of an arbitration clause to which it is a signatory because no such clause exists. At no point did Thomson indicate a willingness to arbitrate. . . ." 64 F.3d at 779.
The Court concluded that, because Thompson was a non-signatory to the contract containing the arbitration provision, it could be estopped from refusing to arbitrate its claim only if it had either directly benefitted from the agreement containing the arbitration clause or had attempted to enforce other provisions of the contract. Id. at 779.