People often forget that although there was never in-fighting up to that point between the two, that Philly under Bruno was often divided 'politically' between the Calabrians and Sicilians. So much so that for a time in Bruno's reign (1960s-early 70s), Joe Rugnetta (Consigliere), a Calabrian was still looked upon as a major authority figure for the Calabrian sects' of the family. Upon Rugnetta's death in 1977, Caponigro was chosen because he too, another Calabrian could fulfill the similar role. So I'll lay out some points:

1. There was 'jealously' that Bruno allowed the Cherry Hill Gambino's, fellow Sicilians to operate in Bruno family territory, this was mainly from Calabrian members of the family. But regardless, nobody in Philly at the time had the pipeline that the Cherry Hill Gambino's had which lead right back to Sicily. And if they themselves wanted to deal heroin, they'd be getting it from the Gambino brothers'.

2. If Bruno despised drug dealing so badly and supposedly wanted to be nowhere near it, why was his primary driver for so many years - Raymond "Long John" Martorano, who was not only Philadelphia's biggest meth supplier but the ENTIRE country's largest supplier at the time? The man was the Meth Kingpin, and we're not talking about simply financing it as you'd see many guys be permitted to do off the cuff, he was an importer. People might claim he wasn't made at that time, but he surely had heat on him, regardless. I think a lot of members also were jealous/angry that Martorano who was extremely wealthy was able to operate with such impunity.

3. The Harry Riccobene Crew dealt in Narcotics, based out of Southwest Philly for 25+ years. Harry (Sicilian) was a made guy, and several members in the crew were made - all dealing drugs. Pete Casella (Sicilian), made guy and subsequent future Underboss under Phil Testa (also Sicilian) had a lengthy sheet and prison record for Narcotics.

4. One of the theories that often doesn't get brought up enough is that Bruno often himself worked direct with associates on very lucrative business interests, which were off-limits to anybody else. For example, Frankie Flowers had major CCTV (Closed Circuit TV) interests all over the country to broadcast boxing, which Bruno got a cut from alongside Flowers massive book - probably the largest in the city at the time. The aforementioned access to Martorano's meth empire, his close relationship with Roofers Union Boss John McCullough, the Kray Brothers in overseas Casino's, etc.

5. Carlo Gambino was gone. He was essentially Bruno's protector. I think this is the major contributing factor - he was vulnerable. I also think its a bit overstated as far as if Bruno was truly as well liked by his family as we're lead onto believe at times and that in the mid-late 70s he was more often found in the company of associates like Long John and Frankie Flowers. Caponigro also had very strong connections to New York, and the NY family crews operating in the North Jersey area. So while the drug dealing "ban" as a whole was probably a factor (Cherry Hill's, Long John, Riccobenes all being permitted), I can't say it was the only factor. As NYMafia stated, AC was also always an 'open city.' I believe any lead way that Bruno supposedly had telling families to stay out was gone once Carlo had passed. IF it was ever brought up via the Commission - how would he have effectively won any vote? He wouldn't have.

Opportunity begets opportunity, Caponigro saw one, and the Genovese saw an opportunity for the double-cross. It really is one of the finest Machiavellian examples in LCN history. What we don't know for sure is what Caponigro brought to Tieri as the primary reasoning for wanting to hit Bruno, but he certainly wouldn't have mentioned a peep about drugs given Gigante/Salerno/Lombardo's stance on it.