Multiple substantial new U.S. import tariffs were in fact implemented in 2025, going well beyond the early‑2025 status quo and forming a central pillar of economic policy, not just rhetoric.

Key developments:

• On February 1, 2025, President Trump signed executive orders imposing 25% tariffs on all goods from Mexico and Canada (with a 10% rate on Canadian energy) and an additional 10% tariff on Chinese imports on top of existing duties; these measures began taking effect in early February and March 2025. (en.wikipedia.org)
• On April 2, 2025 (“Liberation Day”), Trump declared a national emergency over the U.S. trade deficit and signed Executive Order 14257. This imposed a universal 10% baseline tariff on nearly all imports starting April 5, 2025, plus a tiered schedule of higher “reciprocal” tariffs (up to roughly 50%) on countries with large trade surpluses with the U.S. These orders were explicitly framed as a core economic policy to address trade deficits and generate revenue. (en.wikipedia.org)
• Additional, targeted tariffs were layered on: expanded steel and aluminum tariffs to all countries effective March 12, 2025; a 25% global tariff on automobiles and many auto parts starting April–May 2025; and further 2025 tariff hikes on copper, lumber, and furniture, all of which significantly increased effective import taxation relative to early 2025. (whitecase.com)

Because these tariffs:

1. were new and material compared with the pre‑2025 regime, and
2. were actually implemented as major elements of the administration’s 2025 economic policy (not just talked about), Chamath’s prediction that “the tariffs will be a plug… Are they coming? Absolutely.” is borne out by subsequent events.