On Feb. 12, it was confirmed that North Korea tested a ballistic missile as part of the country’s continuing nuclear program. These tests are ultimately aimed at developing nuclear weapons capable of striking the US.

So how concerned should we be about this threat? Experts seem to agree on “somewhat” concerned; it would be possible for North Korea to carry out such a strike but that it is unlikely at the time—although it is possible in the future.

Three main courses of response are possible in relation to this: negotiation, offensive actions and strengthening defense.

The US engaged in negotiations with North Korea in 2005 and 2008, but it is apparent through yesterday’s test that the current strategy of deterrence and negotiation is ineffective.

Another response would be retaliating with force—using bombers or long-range missiles to hit critical North Korean missile launching or test facilities. While this strategy would be effective in removing the country’s military capabilities, it would likely start a war on the Korean peninsula and drag the US into yet another armed conflict—not likely to be a popular decision.

The remaining strategy is increasing America’s missile defense capabilities. Technology has been demonstrated that is capable of shooting down long range missiles, most notably with America’s Terminal High Altitude Area Defense (THAAD) and Israel’s “Iron Dome”, with the former being directed at long range threats and the latter at short range.

However, increasing America’s defense capability in this range is an expensive proposition. This involves radar tracking array installments both in South Korea (for early warning) and on the coast, as well as installation of interceptor missiles and improvements to all hardware and software, all of which will cost big defense dollars.

While many people are skeptical of Trump’s call for increased defense spending, it may be prudent to invest in more missile defenses to protect against a rogue nation that is quickly becoming a rogue nuclear power.