From their latest letter:
From: Jeremy Ben-Ami, J Street
Date: Wed, Feb 15, 2012 at 9:08 AM
Subject: Tell Congress: Sign the bipartisan Ellison-Jones letter on Iran
...Secretary of Defense Leon Panetta has also noted that Iran could retaliate against the United States, “sinking our ships, striking our military bases… not only involve[ing] many lives, but I think could consume the Middle East in a confrontation and a conflict that we would regret.”
The Republican Chair of the House Intelligence Committee Mike Rogers has talked on CNN of the "real problem" that a military strike could cause for the national security interests of the United States4. The Democratic Chair of the Senate's Intelligence Committee Dianne Feinstein echoed Ambassadors Pickering and Luers' call for diplomacy just this weekend.
The J Streeters are actually "American Firsters".