There is plenty of evidence to support the idea of an Iran invasion. Either the US does that directly, or Israel does it by proxy.
1. UN Resolution 1737 calling for Iran to stop Uranium enrichment. Was passed Dec. 23, 2006. Deadline is 60 days. Puts you right into early springtime -- the window of opportunity for warfare -- before the desert heat wrecks havoc on man and machine.
Link:
http://www.un.org/News/Press/docs/2006/sc8928.doc.htm2. Tuesday's headline that should've gathered more attention: Iran is purchasing anti-aircraft missles from Russia.
Link:
http://today.reuters.com/news/articlenews.aspx?type=topNews&storyid=2007-01-16T121314Z_01_L16260588_RTRUKOC_0_US-RUSSIA-IRAN-MISSILES.xml&src=rss&rpc3. The dutch banking/investment firm ING issued a Jan. 9th assessment of what effects a war-on-Iran would bring to the market.
Link:
http://www.rawstory.com/news/2007/Major_investment_bank_issues_warning_on_0115.html4. A Patriot Missle air defense unit from Fort Bliss has been ordered to deploy to the Middle East as part of President Bush's troop surge in Iraq.
Link:
http://www.dallasnews.com/sharedcontent/APStories/stories/D8MJSD4O1.html5. As per the ING document labeled "iraq07a.pdf" (see the rawstory link above), within a month, the US will have a second aircraft carrier battle group in the Persian gulf.
6. A Navy admiral to head Central Command? Doesn't make sense for a ground war.
Link:
http://www.spacewar.com/reports/An_Admiral_For_Iraq_999.html7. Bush, in his Jan. 10th address to the nation says "Succeeding in Iraq also requires defending it's territorial integrity and stabilizing the region in the face of extremist challenges. This begins with addressing Iran and Syria. These two regimes are allowing terrorists and insurgents to use their territory to move in and out of Iraq. Iran is providing material support for attacks on American troops."
Link:
http://www.whitehouse.gov/news/releases/2007/01/20070110-7.htmlAt this point, I don't think we can question whether a campaign will be waged against Iran.
Sadly, I think the proper question would be 'When does it start?'
My (not-so-bold) prediction is that sometime before April, Israel and the US will jointly strike targets inside Iran. The 20,xxx extra troops will be used to seal the border between Iran and Iraq.