You know that old saying that sanctions just creates a bunker mentality for the political interests already in power. In fact, Business Insider has an interesting piece about how isolating these rogue regimes–Iran, North Korea, Sudan, and Syria–actually caused a lot of them to trade with one another and build a substantial homegrown arms industry:
Several countries have managed to build massive arsenals despite being under various forms of international sanction.
China has anti-satellite weapons, advanced fighter jets, and ballistic missiles, despite the US banning all weapons-related trade with Beijing after the 1989 Tienanmen Square massacre.
The Arab League maintains an official boycott on Israel — which nevertheless has the strongest military in the Middle East. And EU and US sanctions haven't wiped out Russia's ongoing military modernization drive.
But China, Israel, Russia face far fewer barriers to the international weapons market than the true rogue states: That is, the US-listed state sponsors of terrorism.
And that's is ironically a source of strength for these countries: They also trade one another, as the above map, compiled with information from the Stockholm International Peace Research Institute's global weapons transfer database for 2014 demonstrates.
Iran provides all sorts of weaponry and military aid to Syria. Though it isn't marked on this map, which shows weapons transfers only from 2014, Iran helped set up Sudan's domestic arms industry and has provided arms to the government in Khartoum that later ended up with pro-government militant groups. Russia and China will sell to just about whomever they want to. Belarus, which has long been under various sanctions because of its government's human-rights record, will also sell to Sudan.
The map above shows one of the consequences of international sanctions and mechanisms like the state sponsors of terror list. They're meant to change regimes' behavior by cutting them off from mainstream trade and international relations. But this actually creates an incentive for them to cooperate with one another in a way that may be even less accountable to responsible international actors.
The publication noted that while Israel, Russia, and China have some “barriers” in the international arms market, they’re not on the U.S. State Departments list for governments that sponsor terrorism.
Additionally, it might depend on the type of sanction imposed; Iran came to the negotiating table over their nuclear program since the sanctions crippled their economy.