Sentence:  On a routine cruise to "<WSD>show the flag</WSD>," the British warships Amphion and Contest steamed into the harbor of Santa Ana Island in the southern Solomons (which are under a British protectorate). 
Meaning of the word marked with <WSD> tags:  Of a naval vessel or military force, to identify itself by displaying the flag of its country of origin, especially in order to establish an authoritative presence and to exert diplomatic or political influence.