The government news site Fresh News has published a piece in English on the new relationship that is possible between the US and Cambodia with the arrival of the new US Ambassador. It is signed "By: Political Observer".
It is very long. Here is the beginning:

Will the New US Ambassador Come to Cambodia with a New Heart Color
08/08/19 12:57
Phnom Penh (FN), Aug. 8 - Over the past years, especially since the July 2013 General Election up until now, the viewpoint and mindset of the overwhelming majority of Cambodian people always consider the term "US Embassy = Opposition Boss" "US Embassy = Headquarter to Topple the Government of Prime Minister HE".

This is the Reality that the US Embassy and US State Department Officials must courageously admit for consideration because I think that the good or bad Cambodia-US relation now depends very much on the new US Ambassador.

While congratulating Mr. Patrick Murphy who will be on diplomatic mission to Cambodia soon, I have also done some researches on multiple websites and found out that he is an experienced diplomat and especially an expert in Southeast Asian affairs. Therefore, I have no doubt that he is well and deeply aware of Cambodia’s both bitter and sweet situation and experiences in the past and at present time, especially he must exactly know what the general population in this country is really in dire need. Thus, my first message to the new US Ambassador to consider is:

1) As what is always said by most people, "Let bygone be bygone" meaning that let the old stuff passes and start to think of new things.

2) I'm also glad when reading an article published by a foreign online newspaper quoted Mr. Murphy’s statement that he would seek to increase up to $3.5 billion dollars in annual trade between Cambodia and the U.S. as well as to strengthen the ties between the American communities and people in Cambodia.
Much more here. http://en.freshnewsasia.com/index.php/e ... 26-13.html

Amid Souring Relations, US Appoints Experienced Asia Diplomat to Cambodia
Murphy will face a government that has pivoted towards China, which has invested billions of dollars and provided geopolitical cover for Cambodia’s poor human rights record.
By VOA Cambodia -
August 16, 2019

Nearly two years ago, W. Patrick Murphy, seated in the U.S. ambassador’s residence in Phnom Penh, addressed reporters and expressed serious concern over a widespread crackdown initiated by the Cambodian government against the political opposition, civil society and independent media.

“When we had said that we had a concern, we also said that we would be required to take measures if there were further backtracking of democracy,” Murphy said in December 2017, then serving as U.S. Deputy Assistant Secretary of State, in charge of Southeast Asia.

In several weeks, Murphy will be at the center of diplomatic work by the U.S. to curb that “backtracking of democracy,” this time in his capacity as the top U.S. diplomat in Cambodia. On August 1, after a nearly one-year delay, W. Patrick Murphy was approved by the U.S. Senate to take over as U.S. ambassador from William A. Heidt, who left the position in late 2018.
In full: https://www.voacambodia.com/a/amid-sour ... 43406.html

HE Directs Government to Renew Cooperation with United States
HE said in the cabinet meeting that the relationship was not starting from the zero mark, instead was a continuation of an existing healthy relationship.
By VOA Cambodia -
October 29, 2019
Cambodian Prime Minister HE advised his government to strengthen frayed relations with the United States, which has been routinely blamed for allegedly aiding an overthrow of the government, according to a Council of Ministers press release on Friday.

In a statement, HE welcomed Murphy’s remarks on non-interference in Cambodia’s internal affairs and that the U.S. did not support any violent overthrow of the government. However, the U.S. embassy in Phnom Penh did not confirm if ambassador Murphy had made those assurances to the Cambodian government.

“In this new context with His Excellency Patrick Murphy as the U.S. ambassador, Prime Minister HE has instructed all ministries, institutions and sub-national administrations to work together to strengthen and extend the good relationship with the U.S.,” the Council of Ministers statement reads.

In full: https://www.voacambodia.com/a/hun-sen-d ... 42364.html