This restriction does not apply to—

1. (a) Purchases at or below the simplified acquisition threshold;
2. (b) Contracts for consumable supplies, provisions, or services for the support of United States forces or of allied forces in a foreign country; or
3. (c) Contracts pertaining to the use of any equipment, technology, data, or services for intelligence or classified purposes, or to the acquisition or lease thereof, in the interest of national security.