ties.” Thus, from the point of view of citizenship, diversity of citizenship (or alienage) is satisfied.
That leaves the amount-in-controversy requirement of § 1332, under which Muscarello had to allege that more than $75,000 is in controversy. She has so alleged, and in the absence of any challenge from the defendants, we see no reason why this should not be the case, especially since this circuit follows the “either viewpoint” rule. See In re Brand Name Prescription Drugs Antitrust Litig., 123 F.3d 599, 609 (7th Cir.1997) (citing McCarty v. Amoco Pipeline Co., 595 F.2d 389, 393-95 (7th Cir.1979)).
B
If Muscarello’s trespass and nuisance claims were ripe, we would be able to consider them. But we conclude, as did the district court, that they are not. This provides an independent ground for dismissal.
The windmills have not been built yet, and so it is difficult to see how they might either be causing a trespass on Muscarello’s land or creating a nuisance. Muscarello tries to argue that the permit itself creates an “interference with her property and her property rights,” but this is too metaphysical for us. We cannot see how the permit, unexercised, causes a trespass or nuisance as Illinois law conceptualizes those causes of action. In re Chicago Flood Litigation, 176 Ill.2d 179, 223 Ill.Dec. 532, 680 N.E.2d 265, 277-78 (1997), provides that nuisance and trespass both require an invasion. Nuisance requires only a perceptible invasion, but the permit did not even lead to this minor effect. Trespass is even tougher; it is usually defined by a “crass physical invasion.” Id. at 205, 223 Ill.Dec. 532, 680 N.E.2d 265. Obviously the permit did not march onto Muscarello’s land, nor, as far as this record shows, did any of the defendants in the effort to start building their wind facility. Limiting her claims to the permit, as she must, Muscarello cannot succeed at this time under either a nuisance or trespass theory.
Y
We next turn to the seven claims for which Muscarello pleaded supplemental jurisdiction pursuant to 28 U.S.C. § 1367. The district court elected to dismiss these claims, as authorized by § 1367(c)(3). We see no abuse of discretion in that action, as far as it goes. The only question is whether, since diversity might provide an alternative basis of subject-matter jurisdiction, the court should have retained them on that basis. Muscarello never asked it to do so, however, and so the question is even narrower: should the court have investigated other potential grounds for its jurisdiction that were not asserted?
It is well established that the burden of establishing proper federal subject-matter jurisdiction rests on the party asserting it — here, the plaintiff. See Kokkonen v. Guardian Life Ins. Co. of Am., 511 U.S. 375, 377, 114 S.Ct. 1673, 128 L.Ed.2d 391 (1994); Merrell Dow Pharm., Inc. v. Thompson, 478 U.S. 804, 809 n. 6, 106 S.Ct. 3229, 92 L.Ed.2d 650 (“Jurisdiction may not be sustained on a theory that the plaintiff has not advanced.”). That said, the rule in this circuit has been that the “court’s discretion to dismiss for lack of subject matter jurisdiction when the plaintiff could have pleaded the existence of jurisdiction and when in fact such jurisdiction exists, should be exercised sparingly.” Hoefferle Truck Sales, Inc. v. DivcoWayne Corp., 523 F.2d 543, 549 (7th Cir. 1975) (citing Littleton v. Berbling, 468 F.2d 389, 394 (7th Cir.1972), rev’d on other grounds sub nom., O’Shea v. Littleton, 414