The imposition of a 10% tariff on Chinese goods imported into the United States “seriously violates the WTO rules,” China’s Ministry of Commerce said in a statement Sunday, adding that China will “resolutely defend its rights.”

That response, at least so far, has been noticeably less concrete than the ones from Mexico and Canada, which were both quick to pledge swift retaliatory tariffs. The latest announcement raises a 10% tariff on Chinese products, rather than the 25% on all goods from Mexico and kraken2trfqodidvlh4aa337cpzfrhdlfldhve5nf7njhumwr7instad onion most from Canada – all are expected to go into effect Tuesday. Unlike for China, where the latest tariffs top existing ones on a swath of goods, Canada and Mexico previously enjoyed nearly a duty-free relationship with the US.

But there are other reasons besides the number next to the percentage sign and China’s public holiday that could account for the comparatively mild response from the world’s second largest economy.