The scale of a combined NATO amphibious landing

What is the largest formation NATO could land in a combined amphibious operation?

A combined British, Dutch, French, Italian, and US Marine effort could likely land a reinforced division in the Atlantic theatre.

The estimate treats amphibious power as a coalition capability rather than counting one nation’s ships in isolation. Combining British, Dutch, French, and Italian marine forces with the US Marine Corps in the Atlantic theatre could make a reinforced-division landing feasible. Interoperability creates an operational scale that none of the European participants could provide alone.