The biggest recent effect in this link in the Interlock has been a result of our response to 9/11 and other acts of terrorism. However, economic and military deals we cut with other countries have also complicated law enforcement internally. Treaties take priority over US law and are considered coequal with the constitution, which means that poorly drafted treaties can cause serious, sometimes unresolvable legal contradictions that greatly complicate law enforcement. Rulings from the World Court, the World Trade Organization, the UN, and other NGOs can also complicate US law and often create paradoxes and enforcement headaches.
Further complications arise when foreign nationals are arrested for committing crimes in the US and the foreign government objects. For example, Mexican officials and news media whipped up considerable anti-US hostility over the arrest, conviction and execution of a drifter from Mexico who had murdered many people over a number of years. Such cases, and the treaty agreements with the various governments, can make the job of local law enforcement much harder.
Poorly drafted drug laws, environmental laws, and labor protection laws can also create bizarrely complicated legal hassles. Jurisdiction is rarely clear and enforcement is often highly arbitrary. In particular, the governmental “wars” on drugs and terrorism create overwhelming pressure on law enforcement and intelligence officials to violate privacy and civil rights at home and abroad and breed controversy and mistrust of government over issues like wire taps, profiling, email intercepts, secret prisons, torture, and drone killings. In many cases, these programs are justified as necessary to stop a greater harm, but then create irresistible opportunities for official abuse. In a climate of low trust in government, they end up undermining that confidence further.
Negotiations with other countries and the status of our relationships with them greatly impact our ability to deal with law enforcement and security problems. As noted elsewhere, one of our continuing problems with our relations with other countries is our need for financial information from them to track down tax evasion, bribery, corruption, and criminal organizations. An ongoing challenge we face is cracking down on tax havens and persuading other countries to give up the easy profits involved in catering to organized crime and other economic criminals. When we make enemies abroad, we increase the number of countries willing to provide safe havens for terrorists and organized crime, which increases our desire to lean heavily on those countries, which in many cases simply alienates them further. There are no easy answers to this problem, but bad laws and unwise treaty obligations can make them substantially worse.