You Don't Get to Pick Your Enemies
I've Googled and Googled, but can't find anything showing that Romania ever declared war on the United States in World War II. And what does that have to do with today's situation in the Middle East? Plenty, if you'll bear with me a moment.
Romania and Germany were allied in the war against the Soviet Union. Romania supplied pretty much its entire army, based mostly in sectors of the Eastern Front where the German High Command didn't expect much fighting. (This helped lead to the disaster at Stalingrad, when Soviet divisions ripped through the Romanian lines on the German flank, leaving the German Sixth Army surrounded in the city.) Great fighters the Romanians weren't. And being tied up on the Eastern Front (or, more correctly, fenced in at Soviet POW camps), they weren't any threat to us.
So what did we do? We bombed the hell out of Romania's oil fields at Ploesti.
We didn't bother taking recon photos to see if Romanian oil was really being sent to German divisions. We didn't look for a smoking gun or for irrefutable evidence. We didn't wait for Romania to declare war on us. We simply did the math: the German war machine ran on oil, and Romania was a friendly source of it.
Does that mean the Army Air Force went off half-cocked, causing a human and environmental disaster without clear reason? Hell, no. We did what was militarily necessary, and lost too many lives in the process.
Now what of Saddam and Osama? They are both our enemies. One, through direct declaration and attack, the other through 12 years of failing to live up to a ceasefire agreement and a series of UN resolutions.
I find the evidence of a direct Iraq/al Qaeda connection to be convincing. Maybe you don't, and that's OK. The point is, it doesn't matter. We're at war. We have two enemies who could collude against us. Letting Saddam off the hook now would be just as silly as allowing Germany the use of Romanian oil in 1943.