That his approach to the Soviets was not correct, and, say, his literal as well as figurative hugging of Brezhnev was ill advised. He made a number of replies, only two or so of which were productive:
Issued an ultimatum that we would not attend the upcoming Summer Olympics held in Moscow if they did not withdraw. That really showed them!
Grain export embargo, which only hurt us, and is generally considered to be immoral in a non-hot war context, as Reagan pointed out.
Reinstated draft registration, which did not go down well after he'd pardoned Vietnam era draft dodgers on his first day in office.
Reversed course with relations with Pakistan, which he'd previously trashed, and with it supported the Mujahideen fighting the Soviets.
In theory reversed course and started rearming, although due to the budget cycle that pretty much had to be proposals that would only be fulfilled by the next president, which of course didn't turn out to be him (note that Wikipedia's entries on him are silent on this general issue, you have to e.g. go to the B-1 bomber page to learn of his canceling it, and how difficult a decision he said it was).