2. White House lawyers tried to hide the reconstructed call transcript — and had done so before.

In the days following the phone call, I learned from multiple U.S. officials that senior White House officials had intervened to “lock down” all records of the phone call, especially the official word-for-word transcript of the call that was produced — as is customary — by the White House Situation Room. This set of actions underscored to me that White House officials understood the gravity of what had transpired in the call.

The whistle-blower writes that White House lawyers “directed” White House officials to remove records of the July 25 call from the system where such documents are normally stored and place it instead in a system for storing highly classified information, like files related to covert actions, even though it did not meet the criteria, in order to limit the number of officials who could see it. A White House official told the whistle-blower that it was an “abuse” of that system to instead use it to hide politically sensitive information.

And in an appendix to the complaint, the whistle-blower wrote that White House officials had said this was “not the first time” that a presidential transcript had been treated in that way, “solely for the purpose of protecting politically sensitive — rather than national security sensitive — information.”

The complaint does not name the White House lawyers. But they would certainly either work for or include the top attorney there — Mr. Trump’s White House counsel, Pat A. Cipollone.

3. The State Department saw Giuliani’s rogue outreach to Ukraine for Trump as a threat to national security.

Starting in mid-May, I heard from multiple U.S. officials that they were deeply concerned by what they viewed as Mr. Giuliani’s circumvention of national security decisionmaking processes to engage with Ukrainian officials and relay messages back and forth between Kyiv and the President. These officials also told me: that State Department officials, including Ambassadors Volker and Sondland, had spoken with Mr. Giuliani in an attempt to “contain the damage” to U.S. national security; ...

The whistle-blower recounts the struggles by the senior United States diplomats to deal with the confusion created by the president dispatching his personal lawyer, Rudolph W. Giuliani, to pressure Ukrainian officials to develop dirt against the Bidens, both in the run-up to the July 25 call and its aftermath. Multiple officials said that Ukrainian leadership was led to believe that any meeting or phone call between Mr. Trump and Ukraine’s new president would depend on whether the latter was willing to “play ball” on Mr. Giuliani’s demands.

4. Trump’s push for investigations coincided with a “sudden change of policy with respect to U.S. assistance for Ukraine.”

I learned from U.S. officials that, on or around 14 May, the President instructed Vice President Pence to cancel his planned travel to Ukraine to attend President Zelenskyy ’ s inauguration on 20 May; Secretary of Energy Rick Perry led the delegation instead. According to these officials, it was also “made clear” to them that the President did not want to meet with Mr. Zelenskyy until he saw how Zelenskyy “chose to act” in office.

This is one of two manifestations of pressure on Ukraine by the Trump administration in advance of the July 25 call. The whistle-blower cautioned that he or she did not know for certain whether this action was connected with the broader understanding that Mr. Trump wanted Mr. Zelensky to “play ball” on Mr. Giuliani’s demands. The whistle-blower recounted the episode in a partly redacted appendix along with a discussion of Mr. Trump’s blocking of the military aid package Congress appropriated to help Ukraine defend itself from Russian aggression:

On 18 July, an Office of Management and Budget (OMB) official informed Departments and Agencies that the President “earlier that month” had issued instructions to suspend all U.S. security assistance to Ukraine. Neither OMB nor the NSC staff knew why this instruction had been issued. During interagency meetings on 23 July and 26 July, OMB officials again stated explicitly that the instruction to suspend this assistance had come directly from the President, but they still were unaware of a policy rationale. As of early August, I heard from U.S. officials that some Ukrainian officials were aware that U.S. aid might be in jeopardy, but I do not know how or when they learned of it.

The appearance that Mr. Trump was using foreign policy as leverage to pressure Ukraine into producing dirt on a political rival is at the heart of the calls to impeach him.