A side effect of President Carter's decision to terminate the military treaty with Taiwan is expected to be a scramble by world arms salesmen to sell modern weapons to Taipei.

Pentagon officials acknowledged last night that they were dismayed to learn that their confidental list of what weapons Taiwan wanted to buy from the United States had just become part of the printed record of a House Budget subcommittee hearing.

Taiwan's wish list includes long-range fighters like the F16, all kinds of battlefield missiles, and sophisticated electronics to enable troops to fight in the dark.

As long as the United States was allied with the Republic of China under the treaty and other ties, Washington had great leverage when it came to deciding what weapons Taiwan could buy. This is no longer the case, because of Carter's decision to terminate the military treaty, effective Jan. 1, 1980, and recognize mainland China as the sole Chinese government.

Taiwan, according to the Pentagon's list of weapons requested, is in the market for fighters that can be used for both bombing and air defense, and wants a whole family of misslies for use against ships, aircraft, tanks, and ground targets.

Also, the list shows that Taiwan wants artillery as big as the 175 mm gun and devices for fighting at night. The U.S. government only recently agreed to sell Israel such secret night fighting gear.

The Carter administration has rejected Taiwan's request for the long-range F16 and F4 fighter bombers and is trying to get the Nationalist Chinese to settle for the shorter range F5 fighter.

But, as part of the backlash to Carter's decision, Taiwan could well end up rejecting Washington's offer of Fks aimed with Maverick missiles and turn to a foreign manufacturer for a hotter plane.

However, the fact that the United States has been Taiwan's supplier for so long means some built-in leverage stemming from the realities of modern weaponry.

For one thing, it would take Taiwan considerable time to work out the same kind of co-production arrangement with another nation it has with the United States for manufacturing the F5. For another, to keep its current U.S.-supplied arsenal working, Taiwan needs a steady flow of spare parts for the immediate future.

In the longer term, Taiwan could break this dependence on the United States and buy from other countries weapons that mainland China would consider a threat to be met in kind, meaning another dimension to the world's arms race.

The administration, partly in hopes of heading off such an arms race between the two Chinas, plans to keep supplying U.S. weaponry to Taiwan as long as it is primarily defensive rather than offensive.

"We plan neither to decelerate or accelerate the flow of wapons to Taiwan," one official said yesterday.