Most partnerships look promising when everything is going well. Expectations are aligned, opportunities are exciting and the incentives for cooperation are clear. In such circumstances, trust, collaboration and shared ambition are easy to demonstrate. The more revealing test often comes later, when circumstances change and interests begin to diverge.

A missed target, financial disagreement, unexpected delay or misunderstanding can reveal behaviours that months of meetings never exposed. Values that sounded convincing during negotiations suddenly become practical choices. How people respond under pressure can provide important information about whether a partnership is capable of surviving the challenges that accompany growth.

This matters because organisations often conduct extensive due diligence on opportunities while paying surprisingly little attention to the people involved. Leaders analyse markets, examine financial projections, negotiate contracts and assess legal risks. Yet one of the most consequential risks in a partnership rarely appears on a spreadsheet: how will the people involved behave when they feel threatened, disappointed or uncertain?

Character is particularly difficult to assess when circumstances are favourable. Someone can appear collaborative when decisions consistently go their way, generous when resources are abundant and trustworthy when trust has never required sacrifice. The better test comes when interests are challenged. Do people ask questions before making accusations? Can they defend their position without becoming destructive? Can they separate the problem from the person?

These behaviours may tell us considerably more about the future of a partnership than the promises contained in a memorandum of understanding. Perhaps organisations therefore need another dimension of assessment alongside financial, legal and operational checks: relational due diligence.

Relational due diligence means paying attention to how prospective partners handle disagreement, uncertainty, delayed gratification and situations where interests are not perfectly aligned. Sometimes the cheapest due diligence is a small disagreement before a large contract.

The principle matters because organisations tend to evaluate opportunities by imagining the consequences of success. A better question is sometimes: What happens if this succeeds with the wrong people? A disagreement when little money is involved may be uncomfortable but manageable. The same conflict after significant contracts have been signed, teams assembled and reputations publicly connected can become extraordinarily expensive.

This does not mean organisations should become cynical. Business depends on trust, and many significant opportunities begin because someone trusts another person enough to make an introduction, share an idea or open a door. Excessive suspicion can be as damaging as excessive trust. The objective is not to eliminate risk, but to understand it better.

Trust should therefore not always be treated as binary. A person may deserve access to a professional relationship without immediately deserving access to a strategic partnership. A prospective partner may be suitable for a limited project before becoming a long-term collaborator. Trust can expand as behaviour provides evidence that greater access is warranted.

Reputation requires particular care because partnerships do not only connect organisations. They connect reputations. Money can be recovered and contracts replaced, but reputation can take decades to build and remarkably little time to damage. Leaders should consider not only what a prospective partner can contribute, but what their behaviour could mean for everyone associated with the relationship.

Perhaps pressure does not necessarily change people. Sometimes it simply gives us access to behaviours we had never previously needed to see. The lesson is therefore not to trust less, but to understand what trust is worth.

The strongest partnerships are not those that never experience pressure. They are those in which pressure can arrive without destroying respect, judgement or the ability to solve problems together. Do not only examine what a potential partner can achieve with you. Observe how they behave when achieving it becomes difficult.

The writer is a brand strategist working at the intersection of business, communication, and growth.