As early as 1625, Hugo Grotius characterized a state's right of self-defense to include the right to forestall an attack forcibly.[6] In 1685, the Scottish government conducted a preemptive strike against the Clan Campbell, called the Argyll Whigs.[7] In 1837, a certain legal precedent regarding preemptive wars was established in the Caroline affair when British forces in Canada crossed the United States border and killed several Canadian rebels and one American citizen who were preparing an offensive against the British in Canada.