Firstly, Trump is going to win the Presidency in 2024. Biden is demented, senile and weak. Also, his support for the Zionist genocide in Gaza means that the Arab American population will sit on their hands rather than vote for him. He will thus lose Michigan, and without Michigan he cannot win.
Secondly, Trump will not be making the decision regarding whether or not top respect US treaty obligations under NATO. I don't think you know how the US government works.
As you may recall, Trump entered office promising to pull the US out of the "forever wars". He was going to get the US out of Afghanistan and he was going to withdraw US troops from Syria.
Well, we all know he was unable to do either of those things. In fact, he ended up bombing Syria and escalating the US presence there.
The fact is that Trump would never be able to unilaterally pull out of NATO, nor would he be able to refuse to honour the US's obligations under a treaty that had been duly ratified by the Senate.
America's leadership in NATO means that all NATO states must "standardise" on NATO weapons systems and munitions - which are overwhelmingly American made. In short, NATO is a giant cash cow for the US military industrial complex. There is no way that the Deep State and the MIC would let Trump derail that gravy train. Congress, which gets huge donatiions from the MIC, would impeach Triump immediately if he made any noises about abandoning NATO.
Moreover, war with Russia in Estonia would be a giant boost for US GDP and would solidify Trump's place as a War President. Do not forget that Trump went to NYMA and he "loves his generals". If his generals tell him he needs to support our NATO allies, he will.