Your explanation is one of the major causes! This matter is considered a classic issue often raised by some Chinese descents complained that mainland China could not help or even so helpless amidst the mass killings etc during the intense Cold War era... those folks could not understand the actual conditions of China at that time, and its strength relative to the adversaries esp. the nonexistent Chinese naval force back then.
But an even much more significant explanation concerning those periods is China was still WEAK AND POOR. Being WEAK & POOR with very limited resources incl. the available ships explained lots of things. Expecting a poor and weak nation to come over to overseas to help... well, there were some, but of course the efforts were naturally limited. WEAK & POOR explained everything! If any one wanna blame, blame it to the "Century of Humiliation", blame it why the minority ruler of Qing dynasty were not blind to ignore rejuvenation and industrialization thus became so weak and easy prey... with very severe consequences carried over centuries later...
One day if China has been operating at least four carrier fleets of class 003 or higher in full combat mode, see if such blatant massacre still happens. Forget not that most of such cases involved the dirty hands of the USA, thus China must always calculate the US strength around. If a nation is still weak and poor, how can it help others in oversea areas???
One particular case like the recent one in Solomon Island, how could one expect China to interfere militarily, or even sent civilian ships to help? It is Solomon govt obligation to provide safety to its people incl those Solomon citizens of Chinese descent; if the legitimate central govt were not capable then asked the UN help then UN Peacekeeping Force can be deployed... that's the right procedure, and in that situation China may help. In Solomon case if it's the central govt that played evil then China might sanction that nation, but the actual case was some internal turmoil between regional actor instigated by foreign power to attack the central govt that wanna be more friendly to China, a gray area domestic affair! China will be bad actor if it ever interferes in such case. Remember, the human rights and safety of citizens and their properties are world's concerns; if country like Solomon can't ensure the safety of its population then capable people and their wealth will relocate; what stay is dependencies and poverty! Anyhow that island nation is too small to be matter... a tiny dot in the world. One suggestion, the Chinese community there must organize themselves to protect their own interests; how can have a Chinatown without some organized power or association to protect itself? At least they can pay a group of mercenary/thugs to protect the venue from the gang violence, organized or not? If they all are too ignorant or selfish then why some blame China for that?
China ain't the Exceptional power that could invade Panama or Granada with impunity... I can't tell about the distant future but for now I am 100% sure of what I think of... whatever one may wish or dream of. Live with reality!
