Has there ever been any foreign threats that directly sought to undermine the collective integrity of the United Kingdom/Great Britain?

by [deleted]

I am quite aware of the nationalist and separatist domestic threats that seek to dissolve the United Kingdom, or at the very least, seek to break away from the crown, but I do not know of any explicit foreign threats e.g. plans publicized or actions taken to carry out that goal from other nations or external/global organizations.

Thank you.

daedalus_x

During the Napoleonic wars the French actively worked for an Irish uprising, including sending a small but military significant French force to assist rebels during the 1798 Rebellion. During World War I and World War II the Germans encouraged Irish separatism, although with sharply limited success.