Editing Freeman Dyson (section)

===Warfare and weapons===
At RAF Bomber Command, Dyson and colleagues proposed removing two gun turrets from [[Avro Lancaster]] bombers, to cut the catastrophic losses due to German fighters in the [[Bombing of Berlin in World War II|Battle of Berlin]]. A Lancaster without turrets could fly {{convert|50|mph|-1|abbr=on}} faster and be much more manoeuvrable.

{{Blockquote | style=font-size:100% | All our advice to the commander in chief [went] through the chief of our section, who was a career civil servant. His guiding principle was to tell the commander in chief things that the commander in chief liked to hear…  To push the idea of ripping out gun turrets, against the official mythology of the gallant gunner defending his crew mates… was not the kind of suggestion the commander in chief liked to hear. |source={{harvnb|Dyson|1979|loc=The Children's Crusade}} }}

On hearing the news of the bombing of [[Hiroshima]]:

{{Blockquote | style=font-size:100% | I agreed emphatically with [[Henry Stimson]]. Once we had got ourselves into the business of bombing cities, we might as well do the job competently and get it over with. I felt better that morning than I had felt for years…  Those fellows who had built the atomic bombs obviously knew their stuff…  Later, much later, I would remember [the downside]. |source={{harvnb|Dyson|1979|loc=The Blood of a Poet}} }}

{{Blockquote | style=font-size:100% | I am convinced that to avoid nuclear war it is not sufficient to be afraid of it. It is necessary to be afraid, but it is equally necessary to understand. And the first step in understanding is to recognize that the problem of nuclear war is basically not technical but human and historical. If we are to avoid destruction we must first of all understand the human and historical context out of which destruction arises. |source={{harvnb|Dyson|1984}} }}

In 1967, in his capacity as a military adviser, Dyson wrote an influential paper on the issue of possible US use of tactical nuclear weapons in the [[Vietnam War]]. When a general said in a meeting, "I think it might be a good idea to throw in a nuke now and then, just to keep the other side guessing…"{{sfn |Dyson|1979|p=149|loc=The Ethics of Defense}} Dyson became alarmed and obtained permission to write a report on the pros and cons of using such weapons from a purely military point of view. (This report, ''Tactical Nuclear Weapons in Southeast Asia'', published by the [[Institute for Defense Analyses]], was obtained, with some redactions, by the [[Nautilus Institute for Security and Sustainability]] under the [[Freedom of Information Act (United States)|Freedom of Information act]] in 2002.){{sfn|Dyson|Gomer|Weinberg|Wright|1967}} It was sufficiently objective that both sides of the debate based their arguments on it. Dyson says that the report showed that, even from a narrow military point of view, the US was better off not using nuclear weapons.{{sfn|Schewe|2014|pp=169–70}}

Dyson opposed the [[Vietnam War]], the [[Gulf War]] and the [[invasion of Iraq]]. He supported [[Barack Obama]] in the [[2008 US presidential election]] and ''[[The New York Times]]'' described him as a [[Modern liberalism in the United States|political liberal]].{{sfn|Dawidoff|2009}} He was one of 29 leading US scientists who wrote Obama a strongly supportive letter about his administration's [[Joint Comprehensive Plan of Action|2015 nuclear deal with Iran]].{{sfn|Broad|2015}}