If, after an employer
furnishes a bond or escrow to a plan under paragraph (3)(B)(ii), the corporation determines that the cessation of the employer
’s obligation to contribute
under the plan (considered together with any cessations by other employers), or cessation of covered operations under the plan, has resulted in substantial damage to the contribution base of the plan, the employer shall be treated as having withdrawn from the plan on the date on which the obligation to contribute
or covered operations ceased, and such bond or escrow shall be paid to the plan. The corporation shall not make a determination under this paragraph more than 60 months after the date on which such obligation to contribute
or covered operations ceased.