* Trump's main response to China was to wage a futile and self-harming tariff war, while at the same time withdrawing from the TPP and thus weakening regional economic co-operation. Trump had neither the experience nor the skill to do China any real harm. His pointless "summit" meetings with Kim Jong-un confused US allies and played into China's hands. The best way to resist China's ambitions is to build a strong Indo-Pacific regional alliance, and Trump did nothing to further that.
* Both the Cuban and Venezuelan regimes easily survived four years of Trump's bluster. In practice, he did nothing to harm them. Again, he failed to build regional alliances that might have helped bring down the Venezuelan regime. The US trade embargo has only served to strengthen the Cuban regime.
* Trump staged a series of photo ops with Arab leaders as they established relations with Israel, but in fact this development had very little to do with him. The driving force was the Saudi regime's desire to form an Arab-Israeli alliance against Iran. The Saudis were happy to allow Trump to take the credit, because that diverted attention from their own nasty regime. In fact, there has been zero progress towards resolving the Middle East conflict during Trump's term. Kushner's amateurish diplomacy achieved nothing. Trump's heavy-handed pandering to Netanyahu was mostly about winning over Jewish voters to the Republican Party, in which he completely failed.
Even we allow Trump some share of the credit that conservatives try to award exclusively to him, this has to be set against the enormous damage Trump has done to the international standing of the US in other areas.
* His pandering to Putin's Russian regime was morally disgusting and strategically damaging, as were his attacks on NATO. Fear of Putin was why he failed to do anything about Syria or to assist the Kurds. We have yet to learn the full story of Putin's hold over Trump.
* His America First trade policies damaged US allies more than anyone - Canada, the EU, Japan and South Korea. His support for Brexit further alienated him from Europe. His complete indifference to human rights issues - even in China - destroyed all the progress Obama had made in restoring the reputation of the US as a champion of liberty.
* His rejection of international co-operation in any form - NATO, the TPP, the WHO, the Iran agreement, the Paris agreement - greatly weakened the power and influence of the US, not to mention its moral standing.
Biden can reverse most of these policies, but it will be many years before any government or any oppressed people again trusts the US to come to their defence, to keep its word, or to take a stand against the oppressors.