Just 2 nations; still a "Coalition?"

I see that “coalition” can be defined as “two or more” but it seems like something that only really applies if it’s a decent crowd of nations or partners. If only the US and UK are going to war in some theater in the world, is it truly a “coalition” or is it a case of
“two’s only a pair; three’s a crowd?”

Certainly, in the UK 2010 general elections we ended up with a coalition government comprised of just two parties.

OK thanks.

Too late to edit OP: If only the US and UK are going to war together as a team in some place of the world…

In Australia, “the Coalition” refers to the more-or-less permanent partnership between two political parties, the Liberals and the Nationals. Ireland has had coalition governments involving two parties, and also others involving more than two parties.

I suspect the “coalition of political parties” sense doesn’t arise very often in the US context, so the context in which most US people encounter the term in in a coalition of states, usually for military purposes - e.g. “the coalition of the willing” that supported the 2003 invasion of Iraq. The military power of the US is such that a coalition with just one other state is unlikely to be strategically significant, so US coalitions would always tend to involve a larger number of states.

But there’s nothing intrinsic in the term to require or suggest more than two. Two bodies can coalesce.

As large and complex as most governments are and the different departments within each that have to cooperate on most joint ventures - yeah; two is a coalition.

Same in Canada - we had a coalition government in WWI, composed of Conservatives and those Liberals which supported conscription.

‘Co’ generally means two. Actually without looking it up the word seems to be meaning from the work itself ‘two in alignment’.

“Co-” just means “together; jointly; in common”, and in fact it’s etymologically related to the “con-” and “com-” prefixes which mean the same thing. Thus people who hold property jointly are co-tenants regardless of how many of them there are, any number of people can coooperate in a project or conspire in a plan, and a community can be any number of people (but usually more than two).