President Donald Trump has had mixed success negotiating deals since taking office.

During the campaign, Trump promised to reshape foreign policy by leveraging his experience negotiating in the private sector. But two recent bills passed in Congress could undermine Trump's next move in his well-publicized trade negotiations with China.

The bills — the Uyghur Human Rights Policy Act and the Hong Kong Human Rights and Democracy Act— address the Chinese government's actions in Xinjiang, a province in Western China, and Hong Kong. The Xinjiang bill condemns "reeducation" camps that detain China's Muslim minorities; the camps have been compared to "high-security prisons, with strict discipline, punishments, and no escapes," according to BBC News. The Hong Kong bill places the US on the side of protestors advocating for greater civil liberties.

Even though backlash from the Chinese government was expected, and swiftly delivered, both bills passed with unanimous consent.

This is just one example of the varied success Trump has had in foreign policy negotiations. He also hasn't been able to persuade Congress to pass his renegotiated NAFTA agreement. He failed at holding one summit with North Korea, and has seemed to quickly take the side of Russian President Vladimir Putin on multiple issues, despite evidence from US intelligence advising him otherwise.

At August's G7 summit, Trump defended his refusal to meet China in the middle. "Sorry! It's the way I negotiate," he told reporters at the conference.

After a year of back-and-forth tariffs, Trump was finally able to secure a truce in December. Yet the president scrapped that deal within months, doubling the tariff rate and drawing the ire of 600 US companies. Just before the G7 summit with the world's most powerful heads of state, Trump put a 10% tariff on all remaining Chinese products and blamed his frustrations on Xi.

Economists argue that tariffs, or taxes on products brought in from other countries, could mean American consumers eventually pay more for common items like bikes and pet supplies, since companies have to make up for paying the higher import fees.

Read more: It's been more than a year since the US-China trade war started. Here's a timeline of everything that's happened so far.

Maurice Schweitzer, the author of "Friend & Foe: When to Cooperate, When to Compete, and How to Succeed at Both," is critical of the president's record so far.

"As a negotiator," the University of Pennsylvania professor says, "he's done a terrible job."

But it's not just a skill for world leaders. Whether asking a boss for more pay, a mortgage broker for a better rate, or a significant other for their buy-in on what series to stream next, bartering populates everyday life — and there is ample research and commentary on how to conduct negotiations effectively.

By studying how Trump's have gone awry, we can inform our ongoing and upcoming negotiations.

A negotiation isn't about winning.

Trump has repeatedly said his goal with China is to "win."

"From Bush 1 to present, our Country has lost more than 55,000 factories, 6,000,000 manufacturing jobs and accumulated Trade Deficits of more than 12 Trillion Dollars," Trump tweeted last year. "Bad Policies & Leadership. Must WIN again!"

But, Schweitzer says, the goal of a good negotiation should be less about winning in the short-term and more about understanding the long-term objectives. Both sides should ultimately feel good about the deal. Implying one side defeated the other won't make for the outcomes you're looking for.

"The best negotiators never talk about winning the negotiation," Schweitzer adds. "The goal of a negotiation like this is to think strategically about what is the long-term goal."

The risk: Negotiators that focus too much on winning over another party are in danger of deadlocking, or being unable to come to an agreement. This could lead one or both parties to abandon the deal altogether. Plus, if a negotiator is overly competitive, the other party may take offense and choose not to continue.

Positional vs integrative bargaining

Trump's strategy seems more positional than integrative: He emphasizes "winning" over "win-win" situations.

Positional bargaining strategies are based on adversarial relationships, "focused on claiming — rather than creating — value," according to Harvard Law School. These negotiations involve each party vying for as much of the pie as they can hold onto, without concern for the interests of others.

Integrative bargaining is based on understanding interests, and negotiating a mutually beneficial agreement. The negotiation isn't one-sided; both parties come to the drawing board and map out a solution based on which destinations carry more weight for either side.

In the book "Getting to Yes," Harvard professors Roger Fisher and William Ury outline how to take an integrative bargaining approach to negotiation. Some key factors are learning to manage emotions within a negotiation, and escaping the cycle of action and reaction which could lead to both parties walking away from the negotiating table.

Come to the table with a plan at hand.

Deals as complicated and intricate as trade negotiations take preparation and focus, Schweitzer says. Preparation usually comes from having an experienced team that can spend time researching different scenarios.

Trump's team, however, did not have much experience in mainstream foreign-policy tactics. Steve Mnuchin, Trump's treasury secretary, ran a hedge fund before taking office. Peter Navarro, Trump's director of trade, has alienated fellow economists with his outlandish ideas. Trump's own inner circle also vehemently disagree with each other at times, leading to screaming matches on one negotiating trip to Beijing.

As a result, China gets mixed messages from what Trump and his team want, adding volatility to the situation.

"Unpredictability is generally pretty bad," Schweitzer says. "His skillset is not well-suited for complex negotiations. Negotiations with China are complicated, and he doesn't have enough expertise on his team to navigate this."

Relationship-building drives successful negotiations

No matter the industry you work in, you're bound to encounter the same people over and over again. Merger and acquisitions lawyers run into the same banks and investors; politicians meet with the same state representatives and city unions; sports agents representing different players meet with the same teams.

In whatever context, Schweitzer says you'll likely be working with the same people "for years or decades."

Hence the need to cultivate relationships.

Since you're set to encounter the same people again and again, negotiating a deal becomes easier if you treat the other party as a friend. People are more likely to strike a deal with people they know and like, Schweitzer has found.

But Trump makes enemies, not friends, Schweitzer says.

Read more: Trump's negotiating team just gave China a trade-war deadline that could have widespread consequences for the US economy

The president's use of name calling results in few friends both among Democrats and within his own party. His bullying may have alienated Republicans when he's needed them the most: the late John McCain, a target for Trump's bullying, voted against a repeal of parts of Obamacare, something Trump promised to do during his campaign.

With China, the relationships are more complicated. The US competes with the country on dominance in the technology space and for influence in the Pacific, yet also collaborates over trade — creating both a "friend" and "foe" situation, Schweitzer adds.

Bullying won't get you a deal.

While China has disadvantaged the US by infringing on intellectual-property rights that have reportedly cost the economy between $225 billion and $600 billion annually, Trump should still have treated the country like a friend and focused on relationship building to sustain a long-term trade deal.

Instead, by focusing too much on beating China, Trump continues to alienate president Xi Jinping and his staff. For instance, the two nations reached a temporary truce in late 2018 after Xi and Trump sat down at the G20 summit in Argentina. Soon after, Trump tweeted he would be escalating the trade war, suddenly forcing China to retaliate.

"The ideal is to focus on building relationships, finding common ground, taking a long-term perspective," Schweitzer says. "The problem is once you burn through relationships, you end up leaving yourself few options of what to do next."

The takeaway: If you want to "win" negotiations, don't burn bridges. Build them.