ON MY MIND By A.M. ROSENTHAL

Craftily, ever so craftily, President Clinton is deceiving the American public about a critical danger to world security: China's international sales of the matériel and technology of nuclear warfare.

The motive is to allow China to buy American nuclear matériel and information, including advanced U.S. nuclear reactor technology -- as U.S. nuclear manufacturers are urging.

No previous President, and not even Mr. Clinton himself until now, would take the step required to permit Chinese nuclear shopping in America -- certifying that China was not illicitly peddling its own nuclear goods abroad.

The U.S. knew that was not true.

The U.S. knew that despite Beijing's denials and pledges, for more than a decade China has made important nuclear sales to countries intent on achieving capability to make nuclear bombs.

Under a 1985 U.S. law, nations illegally proliferating nuclear matériel and technology are subject to American sanctions. They are also forbidden to buy U.S. nuclear products and technology.

Now Mr. Clinton is ready to permit American nuclear sales to China. So last Friday, in his speech setting the stage for the state visit of President Jiang Zemin, he made this statement:

"China has lived up to its pledge not to assist unsafeguarded nuclear facilities in third countries, and it is developing a system of export controls to prevent the transfer or sale of technology for weapons of mass destruction."

Neither part of that sentence is honest.

In 1992, after selling nuclear-war matériel to Iran, Iraq and Algeria among other countries, China signed the worldwide Nonproliferation Treaty against spreading knowledge about nuclear weapons to states that did not possess them.

Three years later, U.S. intelligence discovered that the China National Nuclear Energy Industry Corporation, a Beijing-controlled operation, had sold 5,000 ring magnets to Pakistan, which is trying to match India's nuclear-weapon potential. Experts say that sale could increase Pakistan's weapon capability by jumping its enriched-uranium capacity 100 percent.

The magnets are a product China sold to Saddam Hussein before the gulf war.

The U.S. also found that the magnets went to "unsafeguarded" Pakistani facilities -- no international inspection permitted. Teams of U.N. inspectors have spent almost six years trying to find all of Saddam's "unsafeguarded" hidden nuclear capability.

Violating the treaty should have brought sanctions. Washington complained but imposed no penalty.

China denied the sale. Then on May 11, 1996, it promised not to do it again. Mr. Clinton's speech said nothing about China's nuclear deals and treaty-breaking -- or what the C.I.A. told Congress in June 1997.

The C.I.A. reported that during the second half of 1996, after the pledge to the U.S., China was still the "primary source of nuclear related equipment and technology" to Pakistan. Also, said the report, China is the world's "most significant supplier of weapons of mass destruction-related goods and technology" -- which means nuclear, chemical or bacteriological.

The President did not mention China's breaking its pledge to America after breaking its treaty pledge to the world. Nor did he say that he was planning to reward China by giving it clearance to shop nuclear in America. But he will, unless Congress can block him.

After China's broken pledges, will Americans be fools enough to believe Beijing will keep new promises to become a reformed proliferator or use U.S. nuclear technology for "peaceful purposes"? Just this year, after the usual denials, Beijing admitted that U.S. machinery sold for civilian manufacture was transferred to a military aviation plant.

That Clinton remark about China's developing export controls is cynical acceptance of Beijing's cynical pretense that any illicit nuclear exporting was the fault of sleepy customs officials.

The stuff of nuclear, bacteriological or chemical warfare is not exported from China unless top officials approve. Mr. Jiang is the toppest.

President Clinton is crafty, but not crafty enough. He has turned China's broken pledges into a guilt of his own -- deception about a matter of life and death, many lives and perhaps, some hideous day, many deaths. JOHN KLOTZ Compliments of Proposition One Committee