Virginia government and politics do not exist in a vacuum. The governor does not have the luxury of ignoring the politics or services in the neighboring states. Maryland "owns" the Potomac River, and West Virginia acid mine drainage affects water quality - just as Virginia pollutes the upper watershed of the Big Sandy River.
Delaware fishermen land their catches of horseshoe crabs in Virginia ports, and Norfolk competes head-to-head with Baltimore for ocean-going shipping. Tennessee hospitals provide care to Southwest Virginia residents, cancer patients in Southside go to North Carolina hospitals for treatment - but ambulances travel from Nags Head to Norfolk as well.
"Neighboring" does not mean just the contiguous states either. Water from New York flows into Chesapeake Bay, and winds blowing across Ohio affect air quality at Shenandoah National Park. Traffic from the entire East Coast clogs I-95 - and West Virginia built Corridor H to the edge of Virginia at Great North Mountain in Frederick County.
So Virginia participates in a variety of multi-state agencies, usually with a Federal presence as well. Some disputes involve all the states and require national action rather than agreements between just a few states. In particular, multi-state agreements have been used to address climate change when those states viewed Federal action as inadequate.
Determining the appropriate role of the states to act individually, in partnership, or together in Congress is not a new issue. The Virginia/Maryland trade dispute over control of the Potomac River (and Virginia's threat to close the mouth of the Chesapeake Bay to Maryland shipping) spurred the 1786 Annapolis Conference and highlighted the need for a replacement of the Articles of Confederation.
President Theodore Roosevelt energized the Federal government to confront the trusts, and President Franklin D. Roosevelt expanded the role of the Federal government dramatically with the creation of "alphabet agencies" to deal with the Great Depression. Federal agencies regularly establish national standards in many areas of American life, constraining the flexibility of individual states and reducing the rationale for multi-state agreements.
Geographically, it would not make sense for Virginia to belong to the Northeast Dairy Compact Commission. The Virginia milksheds are different from New England's, and the whole point of the compact is to set a minimum farm price for fluid milk that is above the federally mandated minimum price level to reflect the unique characteristics of the region.