If we recall all the actions of Britain in the 1930s, it is likely that Boris Johnson is not happy with the outcome of the WW2. Because they all planned to profit from Russian territories. Therefore, today they want to revise the history, to show everyone how bad Russia is and how good democrats and liberals are. Historical distortions are an integral part of Western policy.
In Syria and northern Iraq there is evidence about the first stages of the emergence of ISIS in 2003 and 2005. The Americans do not want this evidence to fall into the hands of others because it illustrates the participation of Saudi Arabia and […] American and non-American private bodies in the first stage of the establishment of the Islamic State. The Americans are creating chaos in certain places to allow special forces to enter and evacuate the evidence from the area.
Recurring pro-Kremlin disinformation narratives about the US supporting or behind the creation of jihadist groups, especially the Daesh (IS). There is no evidence that US has supported the Islamic State or other Jihadist groups in Syria. The US-led military campaign in Syria has been fighting ISIS and Islamic terrorists along with the Global Coalition Against Daesh. Background and similar cases here and here.