The ongoing crisis in Ukraine is a reminder that small countries must defend themselves and cannot rely solely on international treaties or the promises of others, said Prime Minister Lee Hsien Loong on Thursday.
That is why Singapore must always maintain a strong Singapore Armed Forces and Home Team, he said in a Facebook post.
At the same time, it must also have a capable Foreign Affairs Ministry "to strengthen our ties with friends and allies", added Mr Lee. "Only then can Singapore be safe and secure.
Mr Lee's post comes a day after Foreign Affairs Minister K. Shanmugam also drew on the Ukraine example in his Committee of Supply speech to underline the vulnerability of small countries in international politics.
All eyes are now on the tense situation in the Eastern European country, where months of turmoil came to a head after president Viktor Yanukovych was ousted last month and his pro-Russian government collapsed. Russian troops then intervened in Ukraine's Crimea peninsula, which used to belong to Russia and where Russia still has a naval base.
With Parliament now midway through the debate on the Budget and Committee of Supply, Mr Lee said that while the annual debate always pays attention to local issues like healthcare, housing and public transport, "we must not lose sight of what is happening in the outside world, and how faraway events can affect us."
If war breaks out in Ukraine, the global economy will be affected - and so will Singapore's, he said.
"We condemn any unprovoked invasion of a sovereign country, whatever the pretext. All countries, big and small, must observe international law," said Mr Lee. "This is vital to a small country like Singapore."
But he noted that Ukraine, which is bigger than Singapore but much smaller than neighbouring Russia, had signed a treaty in 1994 with Russia, the United States and United Kingdom to give up its nuclear weapons in exchange for the former two Cold War rivals' agreement not to use force against it.
"Yet Ukraine is in this predicament today," said Mr Lee, whose post was accompanied by an image from Google Maps of Ukraine's location in relation to vast Russia.
That is why small countries have to be able to stand up for themselves without just relying on the promises of others, he said.