Since the beginning of the Asian crisis, markets and Asia watchers have kept a close eye on China. The main question has always been, ''Despite all China's assurances to the contrary, will it devalue its currency?'' Now it seems that Beijing may truly be preparing for a devaluation.

This remains a prospect, however, that the United States should vigorously oppose.The hidden truth in this discussion is that China has already done a ''stealth'' devaluation by increasing tax rebates on exports, effectively export subsidies. In recent days, China has raised these export tax rebates to 15 percent - the highest level yet. Over the last two years, the list of products eligible for these subsidies has expanded until it covers most manufactured-product categories.

Beijing argues that these rebates are World Trade Organization consistent, and rebates of certain taxes on exports are allowed by WTO rules. But as the United States learned when its Foreign Sales Corporation tax system was found to be a violation of the WTO, defining exactly what tax policy is and what is not WTO-consistent is not an easy matter.

Even if Beijing's vague assurances that these rebates are WTO-consistent are accepted, tax rebates on exports are still undeniably export subsidies. They are subsidies that improve China's trade accounts at the expense of its trading partners. When many of these countries are suffering through deep recessions and China is growing at a 7.5 percent annual rate, these subsidies are understandably controversial.

The fear that Beijing will go beyond these export subsidies and actually devalue its currency arises because China has a long history of devaluations. In the last 15 years, it has repeatedly devalued its currency. Many observers point to China's numerous devaluations aimed at gaining export share as the real underlying cause of the Asian economic crisis. At the very least, it was a contributing factor.

In many ways, export subsidies are actually superior to currency devaluation for China. Devaluing currency has the effect of both subsidizing China's exports and raising import prices. Since many of these imports are used as inputs in its exports, the impact is thus mixed. Further, raising import prices creates inflationary pressure, which has been an ongoing economic concern for China.

In recent days, however, Beijing's interest in devaluation seems to be increasing. Despite increasing subsidies, China's export growth has slowed.

China is finding it difficult to continue running a trade surplus with much of the world still reeling from the Asian economic crisis. Further, deflation seems a more real economic problem than inflation at the present time. Low-priced imports have forced Beijing to lower prices of many products.

The combination of a desire to build exports and a desire to stave off deflation seems to be moving China's leadership in the direction of devaluation. The country's financial leaders have begun to argue that the Chinese currency cannot be maintained at current levels if market forces push it down. These comments are widely interpreted as a warning that a devaluation is coming.

After months of cajoling and pressuring China to maintain its currency value, the resolve of financial officials in the United States and elsewhere seems to be weakening. This is a truly unfortunate signal to send.

It is true there is some limited strengthening in the economies of many of the victims of the Asian crisis. Under present conditions, a Chinese devaluation may not set off an immediate crisis.

Keep in mind, however, that the victims of the Asian crisis need exports to stabilize their economies and get back on a path toward growth. If China devalues its currency to capture export markets, Indonesia, Thailand, and Russia will likely pay the bill in lost exports.

Can China's shrinking trade surplus and deflation problems - all while maintaining growth at more than 7 percent - really be compared to the problems of countries that are in deep turmoil and struggling to recover from one of the most severe economic shocks of 20th century? Under these conditions, devaluation would hardly seem to be the action of a responsible member of the world economy.

Beyond that, consider the direct impact upon the United States. The U.S. trade deficit with China is running at a lot more than $1 billion per week. Part of that deficit is the result of Chinese restrictions that limit U.S. export growth to anemic levels.

Devaluation would push a new wave of Chinese exports into the U.S. market and likely push U.S. exports to still lower levels. As a result, China would certainly replace Japan as the largest source of the U.S. trade deficit.

Faced with these realities, the United States should continue to strongly oppose a possible Chinese devaluation.