Saudi Arabia responded to Canada's criticism of its arrest of women's rights activists by sending a warning to Western countries: mind your own business. New Zealand hasn't spoken up in support of its ally, and a senior lecturer says there's a likely reason.

The Ministry of Foreign Affairs and Trade (MFAT) told Newshub on Thursday the diplomatic spat between Canada and Saudi Arabia is concerning, and it's "encouraging both countries to find a way to move forward".

New Zealand has a "long-standing trading relationship with Saudi Arabia," the ministry said, with exports in 2017 worth $575 million. New Zealand also hosts over 2000 Saudi students.

Is this the real reason New Zealand hasn't spoken up in support of Canada?

Saudi Arabia's allies were quick to voice their support for the conservative Arab kingdom, with the United Arab Emirates, Bahrain, and the Palestinian Authority publicly condemning Canada for interfering in another countries' sovereignty.

Bahrain might be a small country, but it nevertheless took the courage to speak out in support of its ally Saudi Arabia. The two kingdoms share similar values, the same as Canada and New Zealand. So why hasn't New Zealand, or any other of Canada's Western allies, voiced support?

Since Saudi Arabia launched the dispute on Sunday over tweets sent last week by Canadian ambassador to Saudi Arabia Dennis Horak, they have recalled Saudi Arabia's ambassador to Canada, frozen new business and trade, and ordered Saudi citizens seeking medical care in Canada to go elsewhere.

Canadian wheat and barley has also been blacklisted by Saudi Arabia, and the kingdom has ordered the asset managers of its central bank and pension funds to drop Canadian assets "no matter the cost", Global News reports.