Could a coalition take and hold Macau as part of a conflict with China?
Short answerNo: Macau is too integrated with mainland China and too hard to defend, making any attempt a likely strategic and economic disaster.
NotesMacau differs from Hong Kong because of its direct land connection and the difficulty of creating a defensible perimeter. Any assault would confront nearby Chinese forces and risk exhausting anti-tank weapons against a much larger opponent. A successful initial landing would not make the resulting position sustainable.