Before insisting on a military attack on Syria (After Douma the west’s response must be military, 10 April), it might be as well to reflect on historical precedent. In 1936 a revolt broke out in a Spanish province against the legitimate elected government of the republic by half the army. Although intensely disliked by the privileged and the Roman Catholic church in Spain, it was, like Assad’s, the legitimate government of Spain. The League of Nations authorised an arms embargo on Spain which was rigorously enforced by blockade by Britain and France (two substantial maritime empires at the time) in the Mediterranean and Atlantic. As a result, a prolonged civil war ensued with thousands of casualties, with the legitimate government deprived of the resources essential for fighting the rebel forces, while the fascist/Nazi governments of Italy and Spain poured arms and troops (especially air forces) with impunity into the conflict, which lasted until winter 1938.

What was the result of the now inevitable defeat of the legitimate government? Hundreds of thousands of refugees poured into neighbouring countries, where most remained. Forever. A criminal dictator ruled Spain, murdering hundreds of thousands of innocent victims, a dreadful dictatorship ensued for nearly 40 years and the aftereffects continue to this day, as in Catalonia. Be careful what you wish for, Mr Tisdall.

Greg Levitt

Maidstone, Kent

• There can be no justification for chemical weapon attacks, or for despicable bombing that targets civilians of the sort that we saw in Douma. Further military intervention, as proposed by Trump, May or Macron, is not the solution and can only extend the appalling suffering of the people of Syria. It also risks spreading the war across the Middle East and raises the frightening possibility of direct confrontation between nuclear-armed powers.

It is quite wrong to argue, as Tony Blair does, that these attacks are the price of non-intervention. Foreign military intervention from all sides, including from the UK government, has only served to deepen and prolong the war in Syria. Britain voted to join the US in bombing Syria in 2015 and was involved in covert operations before that. Its interventions have killed many people, fuelled the cycle of violence and done nothing to bring peace. Rather than backing the gung-ho foreign policy of the most inflammatory and xenophobic US president in history, the UK government should be seeking political and diplomatic solutions to the tragic situation in Syria, and to avoid anything that can escalate further the conflict in the region.

Mark Rylance, Brian Eno, Francesca Martinez, Owen Jones, Lindsey German, Murad Qureshi, Chris Williamson MP, Emma Dent Coad MP, Ian Mearns MP, Ian Mearns MP, George Monbiot, Giles Fraser, Harry Leslie Smith, Victoria Brittain, Andrew Murray, Kevin Courtney, Manuel Cortes, Kate Hudson, Kiri Tunks, Alex Kenny, Alexei Sayle, Kareem Dennis (Lowkey), Gerald Simpson (A Guy Called Gerald), Lara McNeill, Marcus Barnett, Shelly Asquith, Shelly Asquith, Robin Brookes, Professor Alfredo Saad Filho, Professor Diane Reay, Professor Danny Dorling, Professor Des Freedman, Professor David Miller, Professor Peter Hallward, Dr Feyzi Ismail, Dr Kalpana Wilson, Dr Gholam Khiabany, Dr Tassia Kobylinska, Dr Milly Williamson

• So-called humanitarian interventionism has a very bad track record, both in terms of making lives better for the affected and being abused as a pretext for geopolitical power play. The west has nothing to offer Syria other than to turn it into another Afghanistan or Libya. Unlike Iraq and Libya, Syria has powerful allies who are perfectly capable of standing up to aggressive military bullying by the west. Decisively attacking Syria under current conditions would present US air power with a challenge as big as the Vietnam war.

Currently, the west is suffering from unquestionably bad leadership. Trump and Macron are politically inexperienced leaders elected on impossible-to-meet promises. May is a weak and meek PM unable to impose discipline, even in her own cabinet. Under such dangerous circumstances, I expect the press to exert a moderating influence on politicians and not warmonger.

Matthias Vogelsanger

Zürich, Switzerland

• Your editorial on Syria (11 April) failed even to mention international law. All governments are obliged to obey international law, which expressly forbids interference in the internal affairs of states on any grounds. Article 2 (4) of the UN charter says: “All members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state.”

Will Podmore

London

• Peter McKenna’s description of the anti-government insurgents in Syria as “bizarrely anonymous” (Letters, 11 April) is spot-on. Despite the endlessly repeated mantra of “Assad, backed by Russia and Iran”, we are never told by whom the rebels are supplied with arms. Also curiously absent is the phrase “human shields”– presumably this is only used when civilians are killed by the “good guys”.

Wal Callaby

Ipswich

• Join the debate – email guardian.letters@theguardian.com

• Read more Guardian letters – click here to visit gu.com/letters