Sanctions against Iran-tough enough?

President Carter's movement toward dealing more firmly with Iran stems from both his own impatience with Iranian leaders and from his perception that the public was losing patience with him.

"We don't like to talk about it," one presidential aide said Monday, "but there is a feeling around here that the public's patience with the President is about at its snapping point."

This source insisted that the President's full attention had been given to the safety of the hostages as he shaped his Iranian policy -- with little or no heed to how this p olicy played with US voters.

But this aide said that Mr. Carter had to know that a "growing number" of his own people now felt that he must take a harder line for political reasons.

In assessing the shift in Carter policy, a top political adviser of the President had this to say:

"I think that the President's conciliatory line has been a political liability for some time now. This was what the President had to do -- and what he thought was the best way to deal with the hostages problem.

"But now a harder, firmer position will be much more acceptable with the public."

This source then added:

"The President has been as patient as he could afford to be. It's probably cost him lots of votes -- although it probably was the right position to take."

Washington observers perceive Mr. Carter's latest political and economic moves against Iran as a major political test for the President, who has been falling fast in public approval of late.

Will Mr. Carter be able to rally the American people behind him, as he did in the earlier days of his cautious approach to the release of the hostages?

Or have Americans become so convinced that the President is lacking a well-thought-out policy toward Iran that they will view this new tack as simply another facet of a wishy- washy Carter?

Further, how will the President be able to start getting tough with Iran without frightening many Americans who may feel (1) that this approach could endanger the hostages, and (2) it might be the beginning of a US military involvement in Iran?

The conversation in Washington political circles also centers on this question: Does a new, tougher Iranian line increase the possibility of US involvement in the whole Persian Gulf region?

The President's new policy will gain an early test in the Pennsylvania primary on April 22, where Sen. Edward M. Kennedy is making what could be his last serious attempt to change the course of the primary campaign.

But before then, there may be several twists in the road in terms of US-Iranian relations. Iranian reaction to the Carter fist will be something that the President -- and voters -- will be closely watching.