Could an objection of a minor aged around 10, to returning to his 'home country' be a valid defence, sufficient enough to prevent a Hague Return order after a finding of child abduction is made?

Possibly. Much depends on which 'Hague' country proceedings are being heard. Under the Convention, a child's objection to being returned to his/her country of habitual residence, following proven child abduction, does constitute a defence, if proven, but no specific age is mentioned, and the mechanism provided for considering a minor's views, is subject to differing interpretation, according to domestic law. The child must be 'old' enough and 'mature' enough to have their views taken into consideration, and even if they are considered, they may not necessarily be upheld.
For example in 2010, in a Californian appeal case ( Escobar v. Flores)in the USA, the objections of an 8 year old were upheld, and it stated that no minimum age for the defence could be set, but in a 2013 2nd appeal level Canadian ruling , the objections of a 10 year old in RM v JS ,were not upheld. The Court of Appeal of Alberta, Canada, allowed the mother's appeal , ordering the minor's return to East Jerusalem, qualifying and restricting the defence under the Convention. In this case the parents were both Arab Moslems who had divorced under Sha'aria Court in 2008, in East Jerusalem, Israel and the child was held to have been wrongly retained by the father, at the end of summer visitation with the father, in Canada.

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