There probably isn't a court record of his conviction. If it wasn't reported in the local paper, he's probably fine. There will be a record at the CRB (or whatever they're called today), but the US can't see that.

Is visiting the USA important enough to risk being caught and deported, thus earning a permanent black mark?

The possible risk is more than that - he may also be fined/imprisoned in the US for concealing a material fact when making a presentation to Government. If I remember it correctly, up to 5 years in prison. I've no idea how likely it is on the first offense (probably not likely), but there is still a possibility of having another criminal record, now in US.

@GeorgeY. What do you mean by "presentation to the government"? Immigrant benefits? From the post it appears OP simply wants to visit

@Crazydre I thought that SE best practice was not to suggest ways to avoid or evade what is legal, disclaimer or not.

Well @Dorothy, he's simply not getting into the US otherwise, and I don't see why one should essentially write "you're screwed, full stop" rather than explaining the options in detail

@Crazydre going by that stance, why not suggest someone with a yacht could smuggle him in...?

@Crazydre but the only option is to apply for a visa, as those with conviction for a drug-related offence aren't eligible for the Visa Waiver Program. And it wasn't possession, it was dealing, and unspent, so he's screwed in more than just admission to the US.

@Dorothy Like I wrote, he will not get a visa if he's honest, nor is he technically eligible for a waiver (whether they have discretion in the case of offences committed a long time ago, I do not know, although it certainly does not say so in the relevant law section). If he ever wants to set foot in the US, he'll almost certainly have to lie regardless, so he might as well do it on an ESTA rather than a DS-160.

I would hazard a guess that George's "presentation to the government" refers to the answers/false answers the OP would give to the CBP officer quizzing the OP about entry.

@Crazydre: Tom is correct. This is kind of language used in 18 U.S. Code § 1001

@Tom I see. In any case, despite it being morally questionable and illegal, it's essentially his only way of getting in. The legal doors are shut and unlikely to open again

There are ways to apply for a waiver of ineligibility, dependent on the OP's current or future situations. Suggesting he break the law to do something he is prohibited from doing because he broke the law before is not good advice.

@Tom How does one get a waiver? Could you please let us know according to what section it's possible for drug trafficking? Because the list of ineligibilities and waivers that I linked to makes it clear that drug trafficking is not a crime for which a waiver can be issued

@Tom This whole waiver business feels like a bit of a cop out. It's all very comforting to pretend that obeying the law is always the best course of action and you will eventually be rewarded for it but it's not always true. What if there was no waiver whatsoever, not even the faintest possibility to come back legally behind which to hide ourselves, how would “don't break the law” be a plausible answer?

@Tom I'm not advocating anything and I certainly have no intention to do it myself. But that's all too easy to say for me, I have no criminal convictions and visa-free access to 150+ countries… What I'm saying however is that we should be honest about the actual challenges many people face and precise about the options available and their risks. That means not hiding behind an elusive “waiver” to shy away from the consequences of the “don't break the law mantra” or, conversely, assuming you can't possibly get away with lying because we find it morally objectionable.

Incidentally, what would this “ultimate price” be? Death penalty? Imprisonment? Is there an actual risk of that? Because if it's being refused entry and facing another ban, it must not necessarily seem like a very big risk to someone who is already (effectively) banned. I don't really know either way but this also smacks of wishful thinking.

@Relaxed If you have been issued an entry ban and enter the US illegally, you can indeed be sent to prison. However, if showing up at a port of entry as an ESTA holder who was found out (through media reports, for example) you will simply be sent back.

@Tom Incidentally, I never said I casually break the law, my point is completely different, it's that thinking clearly requires being able to distinguish between moral or legal imperatives and actual risks and consequences. I am not expecting you to change your opinion about anything but I do expect you to present cogent arguments instead of confusion and baseless ad hominem.

@Relaxed - I am amazed how many questions and answers on this website are about getting around the rules, rather than about traveling better. If you want to advise people to lie, bend or break the rules that is your choice. If you don't like my reasoning and answers so be it, I am not here to satisfy your needs. And my "you" in my earlier comment about breaking the law, was more of a universal you applying to all folks who feel a little lie never hurts, not a Relaxed specific you.

@Relaxed - What is the "ultimate price", depends on the situation, caught in the country illegally perhaps jail time, refused entry at the airport loss of non-refundable airfares, hotel and tour bookings. Both cases a black mark with US CBP, info which is shared with other governments such as the Uk, Canada, etc. I suppose you would have been happier if I had put it as "ultimately you will pay the price".

How to smuggle criminals into the US, or how to commit other criminal acts, is probably off-topic here as it isn't something we are likely to be experts on. See How should questions/answers on how to do something illegal be treated?.