Officials could opt to abandon their tightening stance in order to counteract the trade turmoil. But that might erase the gains from the deleveraging.
This explains their restraint so far. At a meeting of the Politburo on July 31st,
China's leaders noted that it was a priority to support growth amid the "clear change" in the external environment,
but also pledged to press on with their efforts to control debt. Investors who had hoped for more easing were disappointed.
So there is cause for concern about China's growth outlook. But markets may be unduly pessimistic.
One conclusion from the past few weeks is that policymakers now accept that the trade war is real, and are starting to cushion the economy.
The boost to exports from the falling yuan, down about 6% on a trade-weighted basis since mid-June,
should be "roughly proportionate" to the blow from the first $50bn of American tariffs and some of the next $200bn,
says Andrew Tilton, the chief Asia economist at Goldman Sachs.
At the margins, he adds, China is shifting to a more active fiscal policy.
Officials have made it easier for cities to get funding for infrastructure projects.
One government adviser says there is discussion of a bigger stimulus, likely to be focused on promoting consumption rather than investment.
The economic backdrop to the trade war could also change over the next year.
As China tiptoes towards easing, its credit growth should pick up.
Meanwhile, America may be near the top of its growth cycle, with gains from last year's tax cut set to dissipate.
Louis Kuijs of Oxford Economics, a research firm, says the divergence in their stock markets might reflect overconfidence in America
and an evaporation of confidence in China. "Both reactions seem exaggerated," he says.
With no resolution to the trade war in sight, there will be time enough to test this proposition.