The correct response is:
The Soviet Union does not trust US foreign policy.
Step-by-step explanation:
This issue can be explained by the concept of defense dilemma.
Many nations in such a bipolar conflict as the one between US and USSR simply do not know if they should 'attack to defend' their territory or wait to see what the other party will do and remain to seem weak.
Thus, both try to one up each other just to secure their own turn against them.
This creates a sort of dilemma and not being sure about each other's motives in these nations.