What is the difference between 涉及 and 涉及到 I'm trying to figure out the difference betwen 涉及and 涉及到. I know here are two examples of each 

当今世界的很多问题都涉及到全球的共同利益 － Could I say 涉及? 

Or
 她的演讲涉及了太多敏感的话题 －  Could I say 涉及到？
Yes and yes. They are pretty much interchangable. Your second example contains 涉及了, marking a completed action, while 到 in 涉及到 is a preposition (to): relating to. You could say 涉及到了 as well, given completion.