The arrest last month of United Nations employee Gennady F. Zakharov on espionage charges and the recent expulsion of 25 alleged undercover KGB agents at the Soviet mission to the UN are being hailed as significant blows to Soviet spy operations in New York City. United States intelligence officials and others stress, however, that much remains to be done in bolstering America's ability to protect its secrets.
Officials say it will take years of work and millions of dollars in extra funding to correct the counterintelligence shortcomings brought into sharp focus in the spy trials of John Walker, Jerry Whitworth, and others who have compromised US defense secrets.
``It is probably going to take us three to four years to really develop [counterintelligence] the way it should be, but the die is cast now,'' says L. Britt Snider, assistant deputy undersecretary for counterintelligence and security at the Pentagon.
``It took 15 years to get into this problem and it is going to take some time to get out of it,'' says Roy Godson, a professor at Georgetown University and an intelligence specialist. ``We have a long way to go.''
In the wake of the so-called ``Year of the Spy,'' Reagan administration and congressional officials have conducted top-to-bottom assessments of US counterintelligence to identify American vulnerabilities to Soviet espionage. Many of the findings are classified, officials say. But here, in general, are the assessments:
Expose a patchwork system of security procedures and clearances that differ markedly from department to department throughout the federal government.
Point up the need to further restrict Soviet and East-bloc diplomats, officials, businessmen, journalists, and tourists in the United States.
Document America's continuing vulnerability to Soviet electronic eavesdropping on telephone calls and data transmissions relayed by microwave or satellite throughout the US.
There are no foolproof ways to stop espionage, officials concede. But they insist that American counterintelligence efforts should be competent to deter people who might consider spying and to make it extremely difficult for dedicated spies to carry out their missions here.
Counterintelligence experts note that in an age when US security depends on sensitive secrets about nuclear weapons, high-tech communications, and the proposed development of a strategic defense, a single well-placed spy could inflict incalculable damage to American security.
``You are essentially looking for a needle in a haystack, and yet that one little needle in the haystack can bring down the whole haystack,'' Mr. Snider says.
The Senate Intelligence Committee is expected soon to release publicly the unclassified version of its massive 18-month study of US counterintelligence. Among the committee's recommendations will be a call for a comprehensive ``National Strategic Security Program,'' designed to organize a unified American response to the threat posed by Soviet and other hostile intelligence services.
The program is intended to ensure that US secrets are as closely guarded in the Pentagon and in Congress as they are at the Central Intelligence Agency and the National Security Agency. To do this, some officials advocate sharply reducing the amount of information considered legitimate secrets, while also reducing the number of people cleared to handle US secrets. (Within the past year, the Defense Department has achieved a 16 percent reduction in security clearances, and as much as a 20 percent reduction in clearances among defense contractors.)
The program is also intended to help even the odds for US counterintelligence agents, who have been outnumbered in recent years by the estimated hundreds of suspected Soviet and East-bloc spies they are expected to watch.
But applying a uniform government counterintelligence policy is expected to be both expensive and controversial. Bureaucratic inertia and battles over turf are seen by officials as potential roadblocks. And with more than 4 million Americans holding security clearances, requiring tougher background investigations or screening programs will cost large sums.
Observers are optimistic that the get-tough mood on Capitol Hill and in the White House will guarantee support for major counterintelligence and security reforms. Congress has increased funding for the Federal Bureau of Investigation, which has primary responsibility in the US for catching foreign spies.
And the White House last year endorsed the concept of restricting the numbers and activities of Soviet and East-bloc officials stationed in the US.
Under current congressional proposals, travel and other restrictions that now apply to many Soviet and East-bloc officials would be extended to cover Soviet-bloc businessmen in the US.
A recent Senate report notes, ``It is clear that certain of these [Soviet-bloc] commercial establishments may be performing activities which pose a threat to US national security.'' The report stresses that ``commercial establishments engaged exclusively in legitimate business activities will not be affected.'' The report does not specify how US officials will determine which businesses are fronts for spies and which are purely commercial.
Congress is also considering allocating $129 million in extra funding to counter Soviet interception of US telephone communications on government-leased telephone lines.
According to US intelligence experts, sensitive government communications are encrypted to prevent interception by Soviet technicians. But most other telephone calls in America are easily intercepted at the large Soviet electronic listening post at Lourdes, Cuba, or with special equipment set up at Soviet facilities in Washington, New York, and San Francisco, experts say.
The concern is that in addition to unprotected sensitive information, the Soviets may be able to snatch from the airwaves details about government officials and others that could be used to identify promising spy recruits.