Now I remember why I quit coming here. Fact checking is very rare on The Donald. How hard is it, really? A quick Google search reveals that something was done about this. An entire bank in Canada where the money was being laundered through was basically shut down and the Justice Dept sued to recover nearly 500 million dollars.

https://www.propublica.org/article/u.s.-sues-to-recover-446-million-from-hezbollah-connected-firms

https://www.hstoday.us/subject-matter-areas/border-security/drugs-laundering-and-used-cars-hezbollahs-criminal-network-breaches-u-s-helps-iran/