万县惨案是1926年9月5日英国军舰轰炸万县城的事件，万县人民因英军的暴行遭受了惨痛的生命财产损失，却没有得到任何道歉或赔偿；而英国却认为其行动目的具有正当性，是为了解救无辜被扣的商轮、惩罚暴虐蛮横的中国军队和保护英国人民的利益。英国海军在万县惨案案前、案中、案后表现出来的心态和行为，都是其“炮舰政策”实施的结果，但惨案后中国各地汹涌的抵英运动使英国为其“炮舰外交”的方式付出了代价，也促使英国的对华政策发生转变。

The Wanhsien Incident was an event where the British gunboat bombed Wanhsien County on September 5, 1926. The people of Wanhsien suffered the tragic loss of life and property due to the atrocities of the British Army, but they did not receive any apology or compensation. The British, on the other hand, believed that the purpose of its action was legitimate, which was to save the innocent vessels detained, punish the tyrannical Chinese army and protect the interests of the British people. The mentality and behavior of the British Navy before, during and after the Wanhsien Incident were all the results of its "Gunboat Policy". However, the surging movement of boycott against Britain from all over China after the incident also made Britain pay the price for its "Gunboat Diplomacy" and prompted a shift in Britain's policy towards China.