There are numerous mountains in Japan and they were an obstacle towards unifying the country. Since many parts of Japan waged wars against others, it was difficult to fight in other people's regions since they had the mountains to their advantage so there was a difficulty in uniting every part of Japan through wars, like it was done in numerous other countries.
Answer:
the use of British bases in the Atlantic
Explanation:
International influence, also they had just defeated Spain when they begun having imperial ambitions, therefore they may want to fill that gap