Do you think the Chinese base in Djibouti has to do with an invasion? This has more to do with the Chinese military being denied staging sites in an area near Australia and New Zealand.
I'm sure you wouldn't want Israel to sign some Security pact with Nepal. That doesn't mean they are going to invade them...however that's puts the potential Israeli military only 800km from your capital.
Because the US Regime thinks China will also do what they themselves usually do, create a military base in Islands. That still may not be problem with the US Regime, but the US Regime thinks it will hinder their ability to enforce their illegal hegemony on the regional countries.