He voiced his solidarity with the weak and defenseless.
他表示自己站在弱势无助群体一边。
《柯林斯英汉双解大词典》
2
Cases such as this demonstrate that even diseases that are not normally fatal can have devastating consequences when they strike an immunologically defenseless community.
What your association is backing is a program which would allow the middle and upper classes to acquire a bomb while poor people will be left defenseless with just handguns.