would be made immeasurably more difficult by the necessity of trying to formulate contract provisions in such a way as to contain the same meaning under two or more systems of law which might someday be invoked in enforcing the contract. Once the collective bargain was made, the possibility of conflicting substantive interpretation under competing legal systems would tend to stimulate and prolong disputes as to its interpretation. Indeed, the existence of possibly conflicting legal concepts might substantially impede the parties’ willingness to agree to contract terms providing for final arbitral or judicial resolution of disputes. Local 174, Teamsters, Chauffeurs, Warehousemen & Helpers of Am. v. Lucas Flour Co., 369 U.S. 95, 103-04, 82 S.Ct. 571, 576-77, 7 L.Ed.2d 593 (1962) (<HOLDING>) (citations omitted). Second, § 301 completely
holding that state court with jurisdiction over  301 claim should have applied federal labor law rather than state contract law holding a state court tort action for retaliatory discharge removable because it arose under  301 of the labor management relations act rather than illinois state law holding state law claim preempted by  301 of labor management relations act only if application of state law requires interpretation of collective bargaining agreement holding that any suit filed in state court alleging violations of a provision of a labor contract must be brought under  301 and be resolved by federal law holding that state law claim regarding breach of settlement agreement was preempted by federal labor law