The phrase "breaks to smithereens" carries a sense of destruction and fragmentation. Its antonym, or opposite, would be something that conveys the idea of wholeness and unity. Some synonyms for this might include words such as "intact," "unbroken," and "solid." Rather than being shattered into tiny pieces, something that remains unbroken suggests strength and resilience. Antonyms for this phrase might also include words like "reinforce," "consolidate," or "preserve." These words suggest a sense of protection or strengthening against potential damage, as opposed to being destroyed into tiny fragments.