Republican presidential contender John Connally today characterized President Carter's handling of the Iranian crisis as "a policy of inaction."

His comments came in response to a question at the second of a series of five news confereces in all sections of South Carolina in which Connally joined the state's two most prominent Republicans, Sen. Strom Thurmond and former governor James B. Edwards, and basked in their endorsements. In 1976, both supported former California governor Ronald Reagan for the Republican presidential nomination.

Thurmond said here that the Iranians never would have taken over the embassy if Connally were president, "because he is too strong, and they would know it."

"The time is going to come in the not too distant future," Connally said, "when I and all Americans are going to ask: what are our policies? What are we doing? Can we succeed, proceeding as we are? At this moment it would appear to nations around the world that we're being toyed with by the Ayatollah Khomeini, much as a cat toys with a mouse. And I think at some point, before too long, we will have to ask ourselves, how effective is this policy?"

Thurmond, 76, looking vigorous and trim, said he is willing and ready "to speak in South Carolina" for Connally. Thurmond seemed to cast himself for a role of regional leadership in the Connally campaign similar to the one he played in 1968, when he held the South for Richard M. Nixon against Reagan.

Connally said he doesn't have to win in South Carolina, whose March 8 Republican primary falls three days before primaries in three other southern states, "but if we can win here, it will give us a temendous impetus going into Alabama, Georgia and Florida."

In addition to Thurmond and Edwards, solicitor (district attorney) Billy Wilkins of Greenville joined in the endorsements.