What did the Bolton manuscript say about Ukraine aid?
A retrospective on the reported claim, made public by 26 January 2020, that Trump tied unfreezing military aid to Ukraine to investigations of political rivals.

What did an unpublished manuscript reveal about the frozen military aid to Ukraine? On 30 January 2020, the question was still at the centre of the 2019 Trump–Ukraine scandal, four days after the manuscript's contents were reported on 26 January 2020.
The manuscript, by former National Security Advisor John Bolton, was for a book titled The Room Where It Happened. According to that report, it said President Donald Trump had told Bolton that unfreezing military aid to Ukraine depended on Ukraine carrying out investigations into Joe Biden and Hillary Clinton.
The wider scandal
The scandal arose from Trump's attempts to press Ukraine to investigate Biden, his political rival, in a way that could damage Biden's campaign for the 2020 Democratic Party presidential nomination. Trump enlisted surrogates in and outside his administration, including personal lawyer Rudy Giuliani and Attorney General William Barr, to pressure Ukraine and other governments.
Trump blocked payment of a congressionally mandated $400 million military aid package, in an attempt to obtain cooperation from Ukrainian president Volodymyr Zelenskyy. Contacts between the White House and the Ukrainian government culminated in a phone call between Trump and Zelenskyy on 25 July 2019.
The manuscript's account tied the aid directly to the investigations, which is why it drew attention in the final days of January 2020.