It more or less goes without saying, doesn't it.  Border patrol has already run down thousands of illegals bringing the stuff across the border, not all of them mexicans either.  Most, in fact, are mosad or chinese. 

https://www.washingtonexaminer.com/policy/defense-national-security/is-immigration-causing-fentanyl-epidemic
 
And truly, that is a STUPID stupid question. Did we have this problem (to this current degree) before?  If not, then what is the answer you should be coming up with?  Mindless teachers want you to believe that 2 + 2 = 5 and that is just ridiculous.  Count on your fingers and see if you can make that equation work out, just once!!!!!!!!  Pathetic.  We have to defend people who are so stupid they don't even know how dumb they are!  About EVERYTHING.  This has been representative of bidens presidency so far.