The tariffs imposed by the U.S. on the European countries are detrimental to USD's position as a reserve currency. A capital outflow out of the U.S. dollar creates positive price pressure on gold via increased demand.
This is true regardless of the U.S. Supreme Court's decision on whether President Trump can lawfully impose unilateral broad tariffs via executive order using the the International Emergency Economic Powers Act (IEEAP).
At the high level, there's two moves for gold here:
➖ If the tariffs are deemed illegal and the collected tariff revenue must to refunded - which would lead to an increase of USD supply acessibilidade to the wider economy. The refund would come either from existing reserves, thus directly increasing broad money or from newly issued debt, which may reduce broad money in the short-term, but the newly issued bonds will eventually be rehypothecated, thus effectively increasing USD credit/effective supply. This is positive price pressure on gold, at the very least due to the increase in liquidity. This is negative price pressure on USD, due to increased supply & public debt of the issuer.
➖If the tariffs are deemed legal, and/or do not need to be refunded, the geopolitical and liquidity risk remains, which materializes in a lower incencitve to own USD. After all, why would you want to hold a currency, whose purchasing power/liqudity may be reduced every other week after the markets close on a Friday? Gold is the natural outflow path from USD, especially at sovereign/central bank level.
If the Eurozone wants to reduce their USD exposure in the next 5 years, what can they do? The European countries may not want to start significantly increasing the share of renminbi in their FX reserves just yet. Additionally, EU could position Euro as an alternative to USD for settlements, as EUR is already the second most used currency for international trade & FX turnover, second only to USD. Gold presents itself as an attractive alternative to USD, even if the focus on increasing its tonnage in the reserves is transitory. At the very least, increasing the share of gold relative to the balance sheet size in the Eurozone, would increase foreign exchange rate value of Euro and/or would provide basis for monetary expansion in the future.
Many forget that the "gold and foreign exchange reserves" are a single asset-side item in central banks balance sheets. "Gold" is explicitly discriminated among all other assets/commodities, while all currencies and their derivatives (e.g. sovereign bonds) are clustered under the generic "FX reserves" name. Across all currencies, renminbi is best positioned to increase its share in reserve assets and international settlement. Unlike renminbi, gold is nobody's liability and has no counterparty risk (assuming no jurisdiction risk, which can be greatly mitigated by storing the gold bullion domestically).
Given this, I expect the European countries to increase their gold holdings, via a combination of swaps from USD-denominated assets for gold and other FX currencies like the Chinese Yen.