I think some of them tried at first but may have been discouraged by the imbalance that obtained then between right and left.
That imbalance will continue even if and when Iran acquires nuclear capability.
The imbalance between US and European participation will continue to grow.
imbalance im·bal·ance (ĭm-bāl'əns)
A lack of balance, as in distribution or functioning.
Lack of equality in some aspect of binocular vision, as in strabismus.