As UNITE HERE opens its national convention today in Chicago, there is still considerable tension and uncertainty in its ongoing battle with Andy Stern and the SEIU.

Labor activist Randy Shaw observes that “[t]he convention should illuminate how other unions view this fight, and whether SEIU will soon find itself not just opposed by UNITE HERE but by much of the labor movement.” He also points out that although Stern has publicly called for UNITE HERE’s John Wilhelm to settle this dispute through binding arbitration (which Wilhelm has vehemently rejected), most of the major union bosses have not backed Stern’s call and will actually speak at the convention.

Shaw notes a particular statement from Stern’s letter to Wilhelm that indicates a far more incendiary fight between the feuding unions may be in store:

What’s most significant about Stern’s letter is that it argues “while to this point we have stood down, if this isn’t resolved by the end of June, we are prepared to respond vigorously to UNITE HERE’s recent hostile actions and defend our union.”

In other words, Stern is saying that if UNITE HERE thought that SEIU was attacking them for months, than that was actually its “stand down” mode — and that all hell could break loose by the end of this week.

That sounds a lot like a threat.

Given the SEIU’s actions against UNITE HERE and other unions (NUHW anyone?) in recent months, it’s hard to imagine at this point what the SEIU has in store if it is “prepared to respond vigorously” to defend itself. What is said (or perhaps, not said) this week at UNITE HERE’s convention may be a good indicator of what is to come.