The Caroline Incident Diplomatic Memorandums US/UK

In 1837 there was a Canadian Rebellion against the Great Britain. Canadian rebels and US citizens were organising aid to the insurgents. The Caroline supplied the force from US shore. The British crossed the Niagara river, international boundary, seized the ship in a US port, set the steamer on fire, and sent her to Niagara Falls. The legality of this preventive action or self defence in foreign territory was discussed diplomatically. There was an agreement between the US and Great Britain on the principle of the inviolability of the territory of independent States, except in cases of self defence.

The American Secretary of State, Mr Webster sent a note to Great Britain: “it will be for Her Majesty government to show a necessity of self defence [necessity of self preservation may be a good defence for certain acts which would otherwise be unlawful], instant [actual and not merely apprehended], overwhelming [the very existence of State is in peril], leaving no choice of means [all legitimate means of self preservation have been exhausted], and no moment for deliberation. It will be for it to show, also, that the local authorities of Canada, even supposing the necessity of the moment of authorised them to enter the territories of the United States at all, did nothing unreasonable or excessive [reasonableness in its exercise], since the act must be limited by necessity and kept clearly within it... A necessity the government of the US cannot believe to have existed”