The federal legislation at the heart of the debate of a Dubai-owned company’s proposed takeover of American port facilities dates back nearly two decades to an era when politicians were more worried about Japan’s economic power than the threat of Middle Eastern terrorism.

“In the ’80s, everyone was very much concerned about Japan buying up the world,” one of the authors of the so-called Exon-Florio provision, James Florio, said in an interview yesterday. “What they were doing was buying a lot of facilities, parks, golf courses, Rockefeller Center. They were also buying a lot of high-tech companies and were perceived as having a corner on the market for semiconductor production,” said Mr. Florio, a Democrat who represented New Jersey in Congress at the time and went on to become governor of the state.

The deal that stirred Congress to act was a proposal by a Japanese electronics firm, Fujitsu, to buy 80% of a leading American chipmaker, Fairchild Semiconductor. Public outcry scuttled the transaction but the debate led to the passage the following year of the Exon-Florio legislation, named for Mr. Florio and a senator from Nebraska, James Exon.

“The sense was at some point down the road, unless something was done, our military would depend on the good will of Japanese computer chip people,” Mr. Florio said. The legislative amendment gave the president the authority to block commercial transactions that could affect American national security. The legislation also set up time frames for reviewing proposed takeovers.

Exon, who served three terms in the Senate, died last year, but a former aide said the late senator’s concern about the foreign-ownership issue began after a British financier, Sir James Goldsmith, mounted an attempted hostile takeover of Goodyear Tire & Rubber Co. in the mid-1980s. Goodyear had a large facility in Nebraska.

“There was a feeling that rubber tires were going to be bought out overseas,” the Exon staffer, Michael Kangior, said. Exon, a Democrat, said such a takeover could put military supplies at risk in the event of war. “He was a national security hawk and always stayed very in tune with an issue like this,” Mr. Kangior said.

In the 1970s, President Ford set up an interagency panel, the Committee on Foreign Investment in the United States. It was created in response to concerns that rising oil prices were helping foreigners acquire critical assets in America. “Suddenly, a lot of oil producing companies had a lot of money and they question was what were they buying in this country?” an attorney who worked on the issue at the Justice Department, Patrick Mulloy, said in an interview. He said a Kuwaiti firm’s takeover of nuclear technology held by an American company was held up using anti-trust laws, but that that many in the government felt a more powerful legal tool was needed to address the issue.

Mr. Mulloy, who was counsel to the Senate Banking Committee when the Exon-Florio measure was adopted, said it was initially opposed by the Reagan Administration. “They were free-investment people,” the former Congressional aide said.

During negotiations on the measure, Congress agreed to give the president broad authority about how the national-security reviews should be conducted and who would conduct them. Lawmakers did specify a 30-day period to review a proposed takeover and a 45-day period for an additional investigation where warranted.

The White House grafted the new process onto the old interagency panel and assigned the Treasury Department to run it.

“If your concern was about national security, that would be the last agency you’d want chairing that group,” Mr. Mulloy said. Out of about 1500 notifications, only one deal has been formally blocked by the president, the takeover of an aerospace firm by a Chinese company. A few dozen transactions are believed to have been withdrawn to avoid a denial, which would be made public.

In 1992,after a company owned by the French government, Thomson, attempted a takeover of an American defense contractor, LTV, Congress strengthened the law further. An amendment sponsored by Senator Byrd, a Democrat of West Virginia, called for a full 45-day review when a company owned by a foreign nation proposed a transaction that could affect national security. This is the provision that many lawmakers claim was short-circuited by the Bush Administration in the Dubai ports deal. Several participants in the drafting of the legislation said yesterday that the 45-day investigation was mandated in this instance. Administration officials insist it was unnecessary, but have now agreed to it.