The 'Grave Risk of Harm' Defence to a Hague Return Application in Ontario

When a parent responds to a Hague Convention application by arguing that returning the child would expose them to serious danger, they're usually invoking what's known as the "grave risk of harm" defence. It's one of the most consequential — and most misunderstood — parts of international child abduction law. This article explains what the defence actually requires, and how evidence of family violence factors into it.

Because these cases move quickly and the stakes are high, this is an area where getting experienced legal help immediately matters more than almost anywhere else in family law.

The Convention's Starting Point: Return Is the Default

It helps to understand the baseline the grave risk defence pushes against. The Hague Convention's general approach is that a wrongfully removed or retained child should be returned to their country of habitual residence so that the merits of any custody dispute can be resolved there — not in the country the child was taken to. Return is treated as the norm; refusing to return a child is the exception, and exceptions are interpreted narrowly.

That framing matters because it explains why the grave risk defence has a high bar. It isn't designed to let a court in the country a child was taken to decide who should have decision-making responsibility, or which country offers a "better" upbringing. It's designed to prevent a narrower, more specific harm: sending a child back into a genuinely dangerous situation.

What the Defence Actually Requires

In general terms, a parent resisting return on this basis needs to show that returning the child would expose them to a grave risk of physical or psychological harm, or otherwise place the child in an intolerable situation. Courts applying this defence typically look for:

• Risk that is serious, not merely undesirable or inconvenient
• A connection between the risk and the return itself — not simply a general preference for one parent's care
• Evidence, not just allegations — courts want to see something more than one parent's unsupported assertions

It is a deliberately narrow exception. A parent cannot succeed simply by showing the other parent is a stricter disciplinarian, has a lower income, or that the child has become more comfortable in the new country.

How Family Violence Evidence Factors In

Family violence is one of the most common — and most legitimate — bases for a grave risk argument. Where a parent can show a documented pattern of family violence, along with a genuine risk that returning the child would recreate or worsen that danger, courts take the argument seriously.

It's worth noting how this connects to, but is legally distinct from, domestic Canadian family law. Under the Divorce Act, family violence and its impact on a person's ability to safely care for and co-parent a child is an express, named factor in the best-interests-of-the-child test used in Canadian parenting disputes. That domestic best-interests framework is not the same legal test as the Hague grave risk defence — one governs whether a child should be returned so the parenting decision can be made elsewhere, the other governs how that eventual parenting decision gets made — but both frameworks take family violence seriously as a substantive issue rather than a peripheral one.

Evidence that tends to matter in a grave risk argument built on family violence includes:

• Police reports or criminal charges related to the family violence
• Medical records documenting injuries
• Prior court findings or orders (such as restraining or protection orders)
• Evidence about the availability, or unavailability, of protective resources in the country of return

What Courts May Weigh Alongside the Risk Itself

Courts don't just ask "is there a risk" in isolation. They often also consider whether protective measures could adequately address the risk while still allowing the return to proceed — for example, undertakings about where the returning parent will live, conditions on contact, or involvement of authorities in the receiving country. Whether such measures are realistic and enforceable in the specific receiving country is often central to how the case is decided.

What the Defence Is Not

A few common misconceptions are worth correcting directly:

• It is not a general "best interests of the child" hearing — that broader question is left to the courts of the country of habitual residence once the child is returned.
• It is not satisfied by showing the child has adjusted well to their new home or has a preference to stay — adjustment and preference are different questions from grave risk.
• It is not a way to relitigate who should have decision-making responsibility going forward — that's a separate proceeding.

Frequently asked questions