A vote by a majority in Britain in the upcoming (June 25) referendum to exit the European Union poses a serious threat to the Northern Ireland economy in the view of several US commercial and political leaders, Democrat and Republican alike.

Each of those interviewed has shown a long-standing commitment to building peace and stability in the North that should give some pause to those seeking to minimize the impact of a “Brexit” from the EU.

Computer software pioneer John Cullinane, a frequent visitor to Northern Ireland who served as an advisor to the Clinton Administration and to virtually all the political parties in Northern Ireland over the years as a champion for US investment, stressed that “business likes stability. This was always one of the big issues in getting companies to locate in Northern Ireland,” he stated from Boston.

Cullinane, who played an influential role in persuading a number of US companies to locate in Northern Ireland, feels a British exit from the European Union would create “instability whether real or imagined.”

Likewise, Jim Lyons, who served as a special advisor to President Clinton for Northern Ireland, bluntly summed up what a Brexit from the EU would mean for Northern Ireland: “The border would be re-instituted and cross-border institutions put in jeopardy, especially all Island tourism and economic development. And direct EU funding would obviously be terminated for Northern Ireland.”

Lyons also underscored that US investment and business to business economic partnerships would also “clearly suffer” and added that “while the Republic would still have the ‘EU gateway’ argument, obviously the North would not.” .

Former Congressman Jim Walsh, a New York State Republican who was his party’s leader on the influential ‘Friends of Ireland Committee’ in the Congress, believes “the free flow of people, goods and commerce” would be hurt on the island overall. Likewise, Congressman Richard Neal, Walsh’s Democratic partner in the Congress in advancing an agenda supporting peace and stability in Northern Ireland, noted that efforts to equalize the corporation tax between the North and South “would mean little if a land border is restored between Northern Ireland and the Irish Republic separating the North from the European Union and more meaningful cross-border cooperation within the island of Ireland.”

“It’s not just history” that lies behind the value of Britain remaining in the EU, Neal said, “it’s also the people, It has been a partner that speaks English in accessing Europe for America.”

Timothy P. Murray, chairman of the Worcester Chamber of Commerce that has some 2,500 members in Central Massachusetts, stresses that “many Massachusetts companies looking to expand business into the European market naturally look to the United Kingdom and Ireland. An exit by the United Kingdom from the European Union will put it at a competitive disadvantage and this will be especially so for Northern Ireland, which has seen significant economic growth over the last two decades.”

The scale of EU investment across a range of social, educational, and infrastructure projects has benefited all communities in Northern Ireland. Almost 150 million pounds have been committed by the European Investment Bank to support the development of Ulster University’s new Belfast campus. While in 2013 alone, the EU invested 5 billion pounds across several sectors of the UK economy, the European Investment Bank also provided 200 million pounds for such important road projects as the upgrading of the MI and M2 motorways as well as for key improvements to large sections of the A1, the A4 and the A5. This in addition to many hundreds of millions in structural fund programs for peace and reconciliation and many millions more for agriculture, fisheries, and overall social inclusion.

The importance of the EU in helping to spur badly needed private sector economic growth in the North is shown by the role of the European Investment Bank in helping to grow the fledging venture capital industry. In providing a total of 13 million pounds in vital investment to Crescent Capital and its first two venture funds the EU helped to spawn venture capital in an area emerging from years of conflict. Its investment in Crescent between 1995 and 2005 saw the development of successful local technology companies like And/or, Lagan, APT, Amino, and Mail Distiller.

With that in mind, Crescent CEO Colin Walsh said, “It would be very countered productive after all that success in my view if Britain and Northern Ireland in particular were to leave the European Union. It has not only helped connect us to important sources of investment capital but also to produce high tech growth and access to the European marketplace as active players. Clearly without this engagement with the EU Northern Ireland rather than going forward would become more peripheral,” Walsh said.

Ironically. a vote to leave the EU could play into the hands of those seeking to stoke up tensions in Northern Ireland and to remove the EU as a significant investment partner throughout Northern Ireland and in the border region.

That is why to many it has been especially perplexing that British Secretary of State for Northern Ireland Theresa Villiers supports leaving the EU and accepting a return to a land border on this island, offering only the anodyne comment that “sensible arrangements“ can somehow be worked out.

That attitude is a throwback to the old ruling class mindset that was content to allow the economic and political clock on this island to go backwards. It also recklessly ignores the hard work done by so many people in both communities with the engagement of the US and the EU to build hope and opportunity.

Dr. Francis Costello is a Belfast-based consultant assisting US and Irish companies.