The official government of Taiwan and its lobby in Washington are, or claim to be, anxious about Taiwan's future in the wake of the new agreement the Reagan administration has just signed with mainland China.
How valid is the anxiety?
Without doubt, China would like to have Taiwan announce that it is rejoining the mainland and accepting the authority of the government in Peking - which, of course, Taiwan has not the slightest intention of doing.
It has no desire to rejoin the mainland for the plain reason that it is enjoying a high level of prosperity on its own, which would be swamped by a lower level were it to rejoin. The people on Taiwan have a per capita income today of $1,820 as compared to $510 on the mainland. Taiwan's economy is growing at a fabulous 8 percent a year rate. There is no comparable figure for the mainland, but it is estimated well below that, if it is growing at all.
For comparison, Indonesia has a per capita GNP of $350 and the Philippines $ 620.
Taiwan is not the richest Asian country by any means. Japan has a per capita GNP of $8,700 - which compares with the US at $9,644. Singapore is probably the richest of the lesser Asian countries at $3,810. But Taiwan is doing well at its ''newly industrialized countries'' of Asia, known as NICs.
Naturally, it prefers to remain autonomous in the Western economic orbit.
But can it be sure of its continuing autonomy if Washington slowly and gradually cuts back on military aid - as Washington agrees to do under its new agreement with Peking?
The answer is that no man can foresee what things will be like in the far Pacific or China very far ahead. Think of how startled almost everyone was on that day 10 years ago when we suddenly learned that President Richard Nixon had gone to Peking. It was the impossible and inconceivable which had happened. More such surprises may lie in the future.
But Taiwan as of today can protect itself comfortably against any military forces which China could, were it so disposed, send against it. True, China has on paper overwhelming superiority over Taiwan in military manpower. But for China to conquer Taiwan it would have to be able to put that manpower on Taiwan. To move an army across the 90 miles of the Taiwan straits would require, first, the consent of the United States and, then, sea and air superiority during the crossing, over the beachhead, and over the supply line indefinitely.
In naval combat vessels Taiwan has 18 post-World War II US destroyers, four more built during the war, and six post-war frigates. Mainland China has 11 post-World War II-type destroyers with three more building, and four former Soviet destroyers built before World War II.
Add that in quality and numbers of modern military aircraft the Taiwanese are capable of preventing any mainland landing force from approaching Taiwan, from establishing a beachhead or supplying such a beachhead. Someday, if it chose, China might be able to build a sea and air force capable of invading Taiwan. It does not have such power today and seems unlikely to have it for many years to come - if ever.
Add also that China's numerically enormous army is largely deployed against the Soviet Union, or against Moscow's Vietnamese satellite, not against Taiwan.
China maintains a total force of 9 armored divisions, 69 main force divisions , and 47 local or militia-type divisions along its border with the Soviets. It has 18 regular and 16 local divisions against Vietnam. Facing Taiwan it has 6 main and 6 local divisions, and no armor.
Finally, the agreement to taper off US arms deliveries to Taiwan is conditional on a promise of China to seek reunion with Taiwan ''peacefully.''
If China threatened Taiwan with force, the deal would be off. Washington would then feel free to send anything it liked to Taiwan.
Meanwhile Taiwan has a growing arms industry of its own. It makes its own fighter planes. It could, if it chose, greatly increase the actual superiority it now enjoys within its own area against anything the mainland Chinese could send against it.
In other words, Taiwan's ability to protect itself has not been injured.
But the deal did delete one factor from the China-Taiwan equation. In effect, Washington has agreed that it will refrain from giving Taiwan the ability to threaten to reinvade the mainland.