Piracy is still alive and well, especially in the Pacific and around nations with less powerful naval defenses. It’s probably to push back against piracy, especially with much the rest of the world turning towards “me first” attitudes and an island nation’s heavy reliance on trade for prosperity. It may also be that the agreement to purchase an aircraft carrier might extend the willingness of other nations to continue helping to protect the trade routes: like it’s a show of good faith that they’re helping too and not putting all the burden on other countries.