No, he didn't. He sat on his arse and did nothing while Syria launched 12 chemical weapon attacks over 12 months (April 2016—April 2017) and finally took action with great reluctance after the 13th attack (also April 2017).
Syria shrugged it off, and launched a further 9 chemical attacks during Trump's term (January 2018—May 2019). Aside from an April 2018 missile strike on three Syrian chemical weapons sites, Trump did **** all about this.
Meanwhile, North Korea continued her missile tests with total impunity, and Russia continued to steal land in Ukraine because Putin knew that Trump was desperate for his respect and would not dare to raise a finger.
Trump's contribution to diplomatic relations amounted to little more than a few petulant tweets, and a failed attempt at détente with North Korea. What did this achieve? Absolutely nothing.
Did Trump end any wars? No. On the contrary, he threatened other countries with war, and enthusiastically maintained every war he'd inherited from Obama.
He refused to withdraw from Afghanistan despite promising to do so during his election campaign, failed to defeat ISIS (another campaign promise) and continued to supply Saudi Arabia and United Arab Emirates with billions of dollars worth of weapons for their war in Yemen.
So who exactly was deterred from doing what, during the Trump presidency? Nobody, and nothing. He was one of the weakest presidents the US has ever seen.
This is demonstrably false.
