I believe that with some strict regulators aimed directly at the organizations that are processing most of the drug cartels financial affairs could reduce the amount of drug smuggling, over time the drug cartels will find out ways to get around the regulations so whatever is put in place has to be constantly changing.
Tighter money laundering laws could definitely reduce illegal drug smuggling. the problem is that most money laundering joints seem completely legite and do good profit themselves. The best accountants are hired, etc. So, while it is good in theory and would work, it would be very hard to implement such laws.
If there were stricter laws in America regarding money laundering, I think it would reduce the illegal act of drug smuggling. When laws are put into place where criminals will have a more difficult time to conduct illegal activities like money laundering, it can only be beneficial in terms of stopping drug smuggling.
The problem with tighter laws to combat drug smuggling is that eventually, the drug smugglers find a way around them. We could tighten money laundering laws, but in the end as all laws like this do, most of the people inconvenienced would be law abiding members of society. Legalize most drugs to solve the problem.
If we have tighter money laundering laws the drug dealers and smugglers will just find another way around those laws or get smarter in how they hide both their money and their drugs. The laws won't do anything in real life just make more challenges for them to find a way around which eventually they will.