This Article was written by FOX Business Network’s Ashley Webster. Ashley Webster joined FOX Business Network (FBN) in September 2007 as the Overseas Markets Editor.

So what happens if the British decide to snub their collective noses at Brussels and say “adios” to the European Union?

By some accounts it will be a disaster for Britain, isolating the European island from the economic might of the EU and putting itself at a distinct economic disadvantage.

Others say that’s all rubbish and the UK will be better off to make its own trade deals while free from the bureaucratic meddling of EU lawmakers.

Either way, the June 23rd vote could have an economic impact in the United States and here’s why?

1. A vote by Britain to leave the EU could create a shockwave in Global markets. Volatility and uncertainty are not good for financial stability and we could see the major markets take a hit, which in turn will hurt your 401-K and other investments. The dust will eventually settle and the best advice is to sit tight and let the markets even out but there’s no doubt it will be a little bumpy for investors.

The fear is that a UK exit could further weaken the European Union as a whole and heighten the risk of a complete collapse. The EU calls this nonsense but the common marketplace has struggled to prop up EU economies that can’t generate economic growth, in particular Greece, and a British departure could create havoc in weaker EU economies.

2. A Brexit will also hurt trade and investment between the UK and America. Trade will continue but trade agreements will have to be rewritten to establish new tariffs and regulations. This won’t happen overnight and could take some time to sort out.

The European Commission says American companies export close to $500 billion worth of goods and services to the European Union, that’s three times higher than US investment in Asia.

Supporters of Brexit say the ability to strike new trade deals is a positive but for US companies it could present a new headache even though it is likely that the two countries will maintain the “special relationship.”

3. Another impact from Britain dumping the EU is the effect on currencies. If the “out” vote wins you will see a drop in the euro and sterling. That means investors will pile into the U.S. dollar as a safe heaven and that will give considerable strength to the greenback which is not great for US companies. A strong dollar would make U.S. exports even more expensive and put US companies at a disadvantage.

Multi-national American companies have already struggled with a strong dollar as recent earnings reports have shown but in times of instability everyone wants the safety of the US dollar and in the vent of Brexit, we pay the price.

4. The timing of the EU referendum also comes at a difficult time for the world economy.

The International Monetary Fund and the U.S. Federal Reserve Board both see Brexit as a big threat to a global economy that’s already struggling to generate any growth.

The UK has been one of the few bright spots following the financial crisis and some analysts say the British economy will see a slowdown in growth equaling 2.2 percent of GDP if voters decide to get out of Europe.

That could have a knock-on effect here in the U.S. meaning investors could see equity prices drop as American companies look to mainland Europe for better opportunities.

5. Another concern for the United States deals is the issue of security and how Brexit could alter the defense landscape in Europe which in turn could have economic implications.

The UK has long been America’s key ally and often a broker for the US in Europe and NATO.

If the UK bows out of the European Union, how much can the US rely on Europe’s commitment to a strong and coordinated defense?

The United States has increasingly put pressure on European nations to play a more active role and take on more responsibilities to keep the continent safe. Even the mention of Brexit has Baltic States feeling nervous as they look over their shoulder at Russia and President Putin’s ambitions.