Taxes are levied to raise money but also to influence behavior. What is taxed and how much influences how much of it is demanded. To take an example of a tariff (tax) on steel imports, the resulting higher price of imported steel increases the relative attractiveness of domestically produced steel. Under the rules of the World Trade Organization, such a tariff would be justified if it offsets an artificial (and thus economic efficiency undermining) subsidy of the foreign produced steel.
President Trump has introduced a totally different way of using tariffs/taxes. He uses them as threats to pressure a country to take action totally unrelated to the item to be taxed. This follows his general bully approach to negotiations. To pressure a country or firm to agree to his requests, he threatens harm if they refuse. If a university or newsman behaves in ways he doesn’t like, he attacks them or threatens them with harm.
In the most recent example Trump is threatening a 50% tariff on all imports from Brazil primarily due to Brazil’s legal proceedings against former President Jair Bolsonaro, which Trump characterizes as a “witch hunt,” and to address what he claims is an “unfair” trade relationship between the two countries.
“Trump demands that the trial against former president Bolsanero, who had tried to instigate a military coup after he had lost the last election, should be immediately end.” “First casualties from Trump’s increasing tariff craze”
It’s not clear what Trump means by “unfair” trade relationship. His positions on trade, which he clearly does not understand at all, are contradictory. He has threatened to raise tariffs on imports from countries that avoid using US dollars in their FX reserves and foreign trade payments. For countries to use US dollars they must have a trade surplus with the US (a US trade deficit with such countries) in order to acquire them. “Why Does the World Need a Reserve Asset with a Hard Anchor?” But Trump doesn’t seem to like or want such deficits. The US actually has a trade surplus with Brazil.
It may sound like this is all from the Onion, but sadly it is not. I don’t expect it to end well.