CONSTRAINTS ON LASER-DRIVEN ACCELERATORS FOR A HIGH-ENERGY LINEAR COLLIDER*

General considerations of the requirements for a high energy linear collider (here, to be specific, taken to be 1 TeV on 1 TeV) are applied to free-space laser and laser/plasma accelerators. It is shown that the requirements impose very severe constraints upon the new accelerators--so severe, that it seems unlikely that these necessary criteria can be met in the foreseeable future.