Despite the cries of outrage from famed investigator Leon Jaworski, the deal to return here the indicated Tongsun Park is the last best hope to prevent the Korean scandal from splitting the United States and South Korea, with shattering implications in the Far East.

The deal, struck after months of hard negotiating by the Justice Department, returns Park as a prosecution witness, not only with immunity from prosecution himself but also with no obligation to testify before Congress. That has led Jaworski to condemn the Carter administration for selling out congressional interests.

However, the Justice Department has informed Jaworski, special counsel for the House Investigating Committee, there is nothing in the deal that bars Park from testifying on Capitol Hill. Indeed, Park's American lawyer hinted that is precisely what would happen, even before the House committee announced this week that it would serve a subpoena on Park the instant he arrives in the United States.

This arrangement is admittedly imperfect. But the alternative would be probable congressional passage of an amendment to the defense appropriations bill cutting off all U.S. funds for South Korea. Added to President Carter's decision to pull U.S. ground troops from South Korea, this would remove effective barriers to invasion from Communist North Korea and split two old allies.

But Jaworski, a national hero as Watergate special prosecutor, is not particularly interested in global politics. Asked by a member of Congress for an opinion, he has declared that an amendment barring Korean aid, similar to the Cambodian-aid ban during the war in Vietnam, is strictly legal and would be upheld in the courts.

Jaworski, in his fury at last week's announcement of the U.S.-Korean bargain on Tongsun Park, contrasted sharply with his opposite number, Milton Kramer, special Korea-scandal counsel for the Senate ethics committee. Karmer termed the arrangement "far from ideal" but praised the Justice Department for having "protected our interests" - that is, the congressional interest. Similarly, the Senate committee will send an official "observer" to Seoul with Justice Department prosecutors when they go there to question Park.

Jaworski, however, refused the departments invitation to do the same. It was not the first such refusal. Deputy Attorney General Ben Civiletti specifically invited Jaworski to accompany him to Seoul with other Justice officials last October when they started bargaining on the Park deal. Civiletti told Jaworski then that the Justice Department could not negotiation on behalf of the House committee. Jaworski declined the invitation.

Jaworski has ignored the clear intent of a statement given by Williams J. Hundley, Park's lawyer here, to United Press International last month. Hundley said that even though testimony before congressional committees was not part of the U.S-Korean deal, he is "prepared to live with" testimony by Park to both the House and the Senate committees.

"Leon is acting strangely," a Senate investigator told us. "He seems to be back in those glorious days of Watergate, when the issue was not Nixon's crime so much as Nixon's coverup. Leon's instinctive reaction to this deal is coverup."

Given Park's role as secret agent of a foreign government out to bribe U.S. congressmen and the fact that Jaworski's predecessor quit the House committee with a coverup charge, Jaworski's suspicious are understandable. But the alternative of all-out pressure on Seoul by banning all U.S. aid might backfire on the United States even more than on South Korea.

Consequently, the Carter administration could not sit back and wait for an anti-Korean explosion on Capitol Hill. So the Justice Department engineered a deal that at the very least will open the door a wide crack to vies some of Park's machinations.

Now that the deal has been struck, Justice Department lawyers can only hope the Korean government will hold up its end of the bargain.

That means obtaining "truthful" testimony from Park in weeks-long questioning in Seoul. It means using Park as a prosecution witness in the first bribery trial - against former Rep. Richard Hanna (D-Calif.) - in February or March. Finally, beyond the terms of the bargain, it means giving Jaworski and the Senate committee full access to Park after the trial.

If that chain breaks down somewhere along the line, Jaworski's ultimate weapon of using U.S. aid as the lever to compel Korean cooperations will undoubtedly be brought into play. That last recourse is so dangerous to U.S. foreign-policy interests that the administration has risked coverup insinuations from coverup expert Leon Jaworski to prevent it.