Prime Minister Justin Trudeau's ​principal secretary Gerald Butts got into some heated exchanges Tuesday morning when he responded on Twitter to criticism of the Liberals' newly unveiled anti-ISIS mission plan.

The response then turned into an intense clash of ideas.

The altercation started when Stephanie Carvin, an assistant professor at Carleton University and researcher at the Norman Paterson School of International Affairs, tweeted comments about the Pentagon's response to the Liberals' new anti-ISIS mission.

Liberals made a choice to stop combat mission - so own it. Justify it. Don't point to Pentagon statements patting us on the head. —@StephanieCarvin

But Butts was quick to respond, arguing the Liberals have always "owned" their decision.

We've only been making this argument for 18 months. We've owned it a long time. <a href="https://t.co/PxvJeW3ohq">https://t.co/PxvJeW3ohq</a> —@gmbutts

The argument took a turn when Steve Saideman, a international relations scholar and fellow at the Canadian Global Affairs Institute, took Butts to task for, in his view, the government's inability to explain its reasoning for pulling six CF-18 jets from the fight against ISIS.

<a href="https://twitter.com/gmbutts">@gmbutts</a> but it is an incoherent argument. Why support combat but not do combat? Is Trudeau a pacifist? —@smsaideman

That led to a long exchange between the two on the most effective way to fight ISIS.

<a href="https://twitter.com/smsaideman">@smsaideman</a> honestly? Our view is equipping locals to fight has the best probability of success. And we've said that 10k times. —@gmbutts

<a href="https://twitter.com/gmbutts">@gmbutts</a> but that does not logically exclude CF18 air strikes. That is the consistent problem--why not? Canada could train and bomb —@smsaideman

<a href="https://twitter.com/smsaideman">@smsaideman</a> because we think our money is better spent on training, where we can add better value. —@gmbutts

<a href="https://twitter.com/gmbutts">@gmbutts</a> ah! there you go: there are finite resources and bigger bang for buck in training than bombing. Did JT say that? didn't see it. —@smsaideman

<a href="https://twitter.com/smsaideman">@smsaideman</a> about 10 thousand times. —@gmbutts

Political researcher Mark Kersten and author Claude Rocan also weighed in.

Important: in Twitter exchange, <a href="https://twitter.com/gmbutts">@gmbutts</a> says policy on <a href="https://twitter.com/hashtag/ISIS?src=hash">#ISIS</a> about added value in training, not principled stance against mil fight. <a href="https://twitter.com/hashtag/cdnfp?src=hash">#cdnfp</a> —@MarkKersten

<a href="https://twitter.com/gmbutts">@gmbutts</a>. Taking a position not the same as making an argument. Don't necessarily disagree, but sure would like to hear the rationale. —@peridotnetworks

The exchange ended with Saideman commenting on the lack of rationale and "muddled" messaging coming from the Liberals.

<a href="https://twitter.com/gmbutts">@gmbutts</a> maybe. But if most of the messaging is getting muddled, it might be partly due to the government's stance and messaging, not public —@smsaideman

Both eventually agreed to disagree.

<a href="https://twitter.com/smsaideman">@smsaideman</a> I dunno Steve. He was pretty clear yesterday. And has been in the house. Always happy to engage with you. —@gmbutts

But things continued with criticism from Conservative party MP Michelle Rempel, who tweeted that Canada is not playing its part in the fight against ISIS, which elicited one more rejoinder from Butts.

Don’t be fooled by the spin — Canada is not playing its full part in battle against ISIL <a href="https://t.co/80EMolYWpl">https://t.co/80EMolYWpl</a> via <a href="https://twitter.com/IvisonJ">@IvisonJ</a> —@MichelleRempel

Yes. NATO? The Pentagon? Allies? All fooled. Only Postmedia columnists & the CPC caucus see the truth. <a href="https://t.co/P4KjnYgZHX">https://t.co/P4KjnYgZHX</a> —@gmbutts