The Land Forces weapons expo, which was targeted in explosive protests on the streets of Melbourne in 2024, will head to Perth in October.
Dozens of police were injured and more than 100 people were arrested in violent and chaotic protests outside the 2024 event.
The Western Australian government committed $10.5 million in its state budget to police the 2026 event but went a step further on Thursday, introducing legislation to grant authorities temporary powers to curb potential protests.
The laws would allow police to declare a protected area with checkpoints and roadblocks and grant them additional powers to search people and vehicles and direct people to leave.
The police commissioner would also be able to exclude certain people from entering the area on safety grounds, while authorities could demand identification without suspecting an offence had occurred.
"In Melbourne, there was serious disruption, many police injured and more than 100 charges for violent and extreme behaviour," WA Police Minister Reece Whitby said.
"Police have intelligence it is likely some of those people involved in what happened in Melbourne would come to Perth to also possibly behave in a similar way."
Mr Whitby suggested Land Forces would be targeted by anti-war, anti-AUKUS and pro-Palestinian demonstrators.
He repeatedly referenced December's Bondi terror attack to justify the proposed laws.
"Police need to be prepared, they need the ability to intervene, to respond to acts of intimidation and threats," Mr Whitby said.
Similar laws were used by Victoria's police during the 2024 protests.
Those powers allowed officers to stop and search vehicles or people in public and ask for identification in specific areas.
It did not prevent chaotic scenes in which wheelie bins were set alight and horse manure, food-grade acid and glass bottles were hurled at police barricades.
Perth will host Land Forces in October before the biennial conference shifts back to Melbourne in 2028.
"This provides a platform for our defence industry … we have the ambition to grow our defence sector to be the second biggest contributor to the state's economy," WA Defence Industries Minister Paul Papalia said.