This has been mentioned in a few posts and really needs to be considered..

"An Iran nuclear deal could mean a new arms race in the Middle East—or improved relations between historic enemies, experts told CNBC.

"To some extent, [a Middle East arms race] is already happening. And it's not just because of an Iranian nuclear program or a deal, it's the threat perception—the perception that Iran is ascendant in the Middle East," said Alireza Nader, senior international policy analyst at the Rand Corp. "

http://www.cnbc.com/2015/07/10/iran-...ce-change.html

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"Some worry that an Iran freed from crippling economic sanctions and the arms embargo could result in greater assertiveness from the Islamic State group. Predominantly Shiite Iran already supports armed groups against its Sunni foe in Iraq, Lebanon and Syria."